Usage:
Introduction
NOTE: For Specifications with illustrations, make reference to SPECIFICATIONS FOR 768C TRACTOR & 769C TRUCK POWER TRAIN, Form No. SENR7807. If the Specifications in Form SENR7807 are not the same as in the Systems Operation and the Testing and Adjusting, look at the printing date on the back cover of each book. Use the Specifications given in the book with the latest date.
General Information
1. Diesel engine.
2. Torque converter.
3. Front drive shaft.
4. Transmission.
5. Rear drive shaft.
6. Differential and bevel gear.
7. Transfer gears.
8. Bevel pinion.
9. Final drive.
LOCATION OF COMPONENTS
The transmission arrangement has a combination of a torque converter (2) and a power shift transmission (4).
The torque converter has an internal lock-up clutch for direct drive and a one-way clutch for torque converter drive. The torque converter is fastened directly to the flywheel of engine (1).
The transmission has seven forward speeds and one reverse speed. The selection of speed is done manually, with a selection lever, in REVERSE, NEUTRAL and FIRST. REVERSE is torque converter drive only. FIRST has both a torque converter drive and a direct drive range. SECOND through SEVENTH speeds are direct drive only with a very short time of converter drive during clutch engagement to make shifts smooth. The transmission is fastened directly to the main frame. Transfer gears (7) are fastened directly to the transmission.
Front drive shaft (3) is the connection between torque converter (2) and transmission (4). Torque is sent through transfer gears (7) to the input gear of transmission (4).
Power is sent from the flywheel of diesel engine (1) through torque converter (2), front drive shaft (3), transfer gears (7), to transmission (4). The power take-off drive of the transmission sends power through rear drive shaft (5) to bevel pinion (8) and differential and bevel gear (6). The axles are connected with splines to the differential and the sun gears of planetary final drive (9). When the axles turn, the planet gears are moved with force to turn on the inside surface of the ring gear. The ring gear is fastened to the final drive hub and can not move. The planet carrier is fastened to the wheel and power is sent to the tires.
Power Train Hydraulic System
1. Oil cooler for the torque converter and brakes.
2. Oil filter for the transmission.
3. Oil filter for the torque converter.
4. Brake control valve (on transmission case).
5. Torque converter.
6. Inlet relief valve.
7. Shift cylinder group.
8. Transmission hydraulic controls.
9. Outlet relief valve.
10. Transfer gears.
11. Transmission.
12. Breather line.
13. Scavenge oil pump for the transmission and torque converter.
14. Magnetic screen.
15. Steering hydraulic pump.
16. Oil pump for the transmission and torque converter.
17. Oil pump drive.
18. Hoist hydraulic pump.
19. Sequence and pressure control valve (on transmission cover).
20. Brake cooling circuit.
21. Hydraulic oil tank.
POWER TRAIN HYDRAULIC SYSTEM
The components of the hydraulic system are reservoirs (three), pumps (two), oil filters (three), transmission hydraulic controls, and an oil cooler.
There are three reservoirs in the system. The main reservoir is hydraulic oil tank (21), which is the common reservoir for the power train, hoist and brake cooling circuits. Hydraulic oil tank (21) has a filter in it to remove foreign material from the oil that comes from scavenge oil pump (13) for the torque converter and transmission. The hydraulic oil tank is fastened to the outside of the left hand frame between the fron and rear wheels.
Another reservoir is in the bottom of the torque converter cover. It gets oil that has drained from oil pump drive (17) and torque converter (5). The torque converter section of scavenge oil pump (13) sends this oil back to hydraulic oil tank (21).
The bottom of the transmission case is also a reservoir. It gets oil that has drained from the planetaries of transmission (11) and transmission hydraulic controls (8). The transmission section of scavenge oil pump (13) pulls this oil through magnetic screen (14) and sends it back to hydraulic oil tank (21).
Oil pump (16) for the transmission and torque converter pulls oil from hydraulic oil tank (21). The transmission section of the pump sends oil through oil filter (2) and on to transmission hydraulic controls (8). This oil will activate the clutches of the transmission and also release the rear brakes.
The torque converter section of oil pump (16) sends oil through oil filter (3), inlet relief valve (6), torque converter (5) to outlet relief valve (9). Extra oil from inlet relief valve (6) goes back to hydraulic oil tank (21). Extra oil from outlet relief valve (9) goes to oil cooler (1). Part of this oil goes to oil pump drive (17) for lubrication. The remainder of this oil goes to oil cooler (1) and brake cooling circuit (20) and back to hydraulic oil tank (21).
Breather line (12) prevents an increase in pressure inside oil pump drive (17), torque converter (5), and transmission (11).
Oil Pump For The Transmission and Torque Converter
LOCATION OF THE OIL PUMP
1. Pump.
Oil pump (1) for the transmission and torque converter is fastened to the lower rear side of the oil pump drive. The pump gets oil from the hydraulic tank and sends it under pressure to the rest of the power train hydraulic system.
Oil pump (1) has two sections, one for the transmission and one for the torque converter. Body assembly (3) is the transmission section of the pump. Body assembly (4) is the torque converter section of the pump.
Drive gear (7) has splines and is driven by a gear in the oil pump drive. Drive gear (6) is fastened to drive gear (7) by a key.
Drive gear (7) turns driven gear (9). Driven gear (10) turns on driven gear (9). Drive gear (6) turns driven gear (10).
The inlet side of both sections of the pump are connected. The oil goes into body assembly (4) for the torque converter. The oil also goes to body assembly (3) for the transmission. This oil fills the spaces between the gear teeth.
Drive gear (7) and driven gear (9) turn and the oil is sent out of body assembly (3) and manifold assembly (2) to the transmission and its valves and components.
Drive gear (6) and driven gear (10) turn and the oil is sent out of body assembly (4) to the torque converter and its components.
COMPONENTS OF THE OIL PUMP
2. Manifold assembly. 3. Body assembly. 4. Body assembly. 5. Cover assembly. 6. Drive gear. 7. Drive gear. 8. Bearings. 9. Driven gear. 10. Driven gear.
Oil Pump Drive
Oil pump drive (1) is fastened to the inner left side of the main frame directly behind the flywheel housing of the engine. The accessory drive gear in the flywheel housing drives pump drive shaft (2). Pump drive shaft (2) is connected to yoke assembly (6).
Splines connect yoke assembly (6) to drive gear (7). Drive gear (7) turns idler gear (9) which turns driven gear (15).
LOCATION OF OIL PUMP DRIVE
1. Oil pump drive. 2. Pump drive shaft (under guard).
COMPONENTS OF OIL PUMP DRIVE
3. Shims. 4. Housing. 5. Bearings. 6. Yoke assembly. 7. Drive gear. 8. Cage. 9. Idler gear. 10. Shims. 11. Shaft. 12. Bearings. 13. Cage assembly. 14. Bearings. 15. Driven gear. 16. Shims.
Shims (3) are used to adjust the end play of drive gear (7). Shims (10) are used to adjust the end play of idler gear (9). Shims (16) are used to adjust the end play of driven gear (15).
Three pumps are driven by the oil pump drive. The hoist pump is fastened to cage (8) and is driven by drive gear (7). The oil pump for the transmission and torque converter is fastened to cage (13). The steering pump is fastened opposite the oil pump for the transmission and torque converter, directly to housing (4). Driven gear (15) drives both the steering pump and the oil pump for the transmission and torque converter.
Lubrication of the oil pump drive is provided by oil from the brake cooling oil circuit. The oil is put (sprayed) on to drive gear (7). Holes, in housing (4), send oil to each bearing. An oil level is kept in housing (4) so that the teeth on driven gear (15) are in oil. The gears throw oil around in the housing. Extra oil in housing (4) goes to the torque converter cover.
Oil Filters For The Transmission And Torque Converter
LOCATION OF THE OIL FILTERS
1. Transmission oil filter. 2. Torque converter oil filter.
The oil filters for the transmission and torque converter are fastened to the inner right side of the main frame behind the torque converter. Oil from the hydraulic tank goes to the oil pump for the transmission and torque converter. The transmission side of the pump sends oil to transmission oil filter (1). The torque converter side of the pump sends oil to torque converter oil filter (2).
The operation of both filters is the same. Oil goes through inlet passage (6) and fills the space between the inside of housing (10) and element (9). During normal operation, the oil goes through element (9) and outlet passage (7) to the remainder of the hydraulic system. Element (9) stops any debris that is in the oil.
COMPONENTS OF THE OIL FILTERS
3. Bypass valve. 4. Spring. 5. Plug. 6. Inlet passage. 7. Outlet passage. 8. Base. 9. Element. 10. Housing. 11. Plug.
If the filter element becomes full of debris, the restriction to the flow of oil causes a pressure increase inside the filter. The pressure oil causes bypass valve (3) to move against the force of spring (4). The oil then goes past the open bypass valve and to the remainder of the hydraulic system. When the oil does not go through the filter element, the debris in the oil will cause damage to other components in the hydraulic system.
Correct maintenance must be used to make sure that element (9) does not become full of debris and stop the flow of clean oil to the hydraulic system.
Magnetic Screen
Magnetic screen (1) is fastened to the front of the transfer gear case. Oil from the bottom of the transmission case goes through inlet passage (7). As the oil goes through screen (4), foreign particles that are in the oil are stopped by the screen and can not go into the hydraulic system.
LOCATION OF THE MAGNETIC SCREEN
1. Magnetic screen.
After the oil goes through screen (4), it goes around and through magnets (5) and tube assembly (6). The magnets are installed on the tube assembly so that the same magnetic ends are next to each other. Smaller metal particles that go through the screen are stopped and held by magnets (5). These magnets will not let the metal particles go with the oil through the hydraulic system.
The oil then goes through outlet passage (2) to the transmission side of the scavenge pump.
COMPONENTS OF THE MAGNETIC SCREEN
2. Outlet passage. 3. Housing. 4. Screen. 5. Magnets (three). 6. Tube assembly. 7. Inlet passage.
Scavenge Oil Pump For The Torque Converter And Transmission
LOCATION OF THE OIL PUMP
1. Oil pump.
Scavenge oil pump (1) for the torque converter and transmission is fastened to the rear of the torque converter cover. The pump takes the oil that goes to the bottom of the torque converter cover and transmission case and sends it back to the hydraulic tank.
Scavenge oil pump (1) has two sections, one for the torque converter and one for the transmission. Body assembly (3) is the torque converter section of the pump. Body assembly (4) is the transmission section of the pump.
COMPONENTS OF THE OIL PUMP
2. Cover assembly. 3. Body assembly. 4. Body assembly. 5. Manifold assembly. 6. Drive gear. 7. Drive gear assembly. 8. Bearings. 9. Driven gear. 10. Driven gear assembly.
Drive gear assembly (7) has a gear fastened to it. This gear is driven by a gear on the torque converter. Drive gear (6) is fastened to drive gear assembly (7) by a key.
Drive gear assembly (7) turns driven gear assembly (10). Drive gear (9) turns on driven gear assembly (10). Drive gear (6) turns driven gear (9).
Oil, from the bottom of the torque converter, goes through a screen and through the torque converter cover. The oil then goes through a passage in body assembly (4) to body assembly (3). The oil fills the space between the gear teeth. Drive gear (6) and driven gear (9) turn and the oil is sent out of body assembly (3), through body assembly (4) and manifold assembly (5).
Oil from the bottom of the transmission goes through a magnetic screen to manifold assembly (5). The oil goes through a passage in manifold assembly (5) to body assembly (3). The oil fills the space between the gear teeth. Drive gear assembly (7) and driven gear assembly (10) turn and the oil is sent out of body assembly (4) and through manifold assembly (5).
The outlet sides of both section of the scavenge pump are connected. The torque converter oil from body assembly (3) is mixed with the transmission oil in body assembly (4). Together, this oil goes out through manifold assembly (5) to the hydraulic tank.
Oil Cooler For The Torque Converter And Brakes
LOCATION OF OIL COOLER
1. Engine oil cooler. 2. Oil cooler for torque converter and brakes.
Oil cooler (2) for the torque converter and brakes is fastened to the right side of the engine cylinder block. Engine coolant, from the water pump, goes into the oil cooler at the front of the engine. The coolant goes through long tubes in oil cooler (2). The coolant then goes into the engine cylinder block at the rear.
Torque Converter
The torque converter is driven by the engine flywheel. It is made up of an impeller, turbine, lock-up clutch, and a stator with a one-way clutch. The lock-up clutch permits the machine to operate in direct drive to keep the power loss to a minimum. The one-way clutch holds the stator when the torque converter is used and lets the stator turn freely when the torque converter is not used. The converter cover is fastened directly to the flywheel housing and provides an oil reservoir and a place to fasten two valves and a scavenge pump. The flange of the output shaft of the torque converter is connected to the front drive shaft.
The transmission is driven by the torque converter in first, neutral, and reverse. During shifts from second through seventh speeds, the torque converter is activated for a moment (the lock-up clutch disengages for a moment) to make the shifts smooth. Once the transmission clutches are engaged, the lock-up clutch engages and the transmission is in direct drive.
In first speed, the operation of the lock-up clutch is controlled by the output speed of the transmission. The transmission can be in either torque converter or direct drive in first speed.
NOTE: For information on the inlet and outlet relief valves and the sequence and pressure control valve, see TRANSMISSION HYDRAULIC CONTROLS.
Torque Converter Drive
1. Rotating housing.
2. Turbine.
3. Impeller.
4. Drive gear for the torque converter and transmission scavenge pump.
5. Inlet passage for converter oil.
6. Outlet passage for converter oil.
7. Stator.
8. One-way clutch.
9. Carrier.
10. Hub.
11. Lock-up clutch.
12. Plate.
13. Hub.
14. Carrier.
15. Output shaft.
FLOW OF OIL AND POWER IN TORQUE CONVERTER DRIVE
The engine flywheel turns rotating housing (1) which turns impeller (3). The impeller moves (directs) the oil to the blades of turbine (2) and causes the turbine to turn. The turbine directs the oil to stator (7) and causes the stator to try to turn in the opposite direction of the turbine. The movement of the stator causes the rollers of one-way clutch (8) to move (roll) between stator (7) and carrier (9) for the stator. The action of the one-way clutch keeps the stator from rotation. The stator now directs most of the oil back to impeller (3). The remainder of the oil goes out of the torque converter through outlet passage (6). The oil, that goes back to impeller (3) from stator (7), moves in the same direction as the rotation of the impeller.
Turbine (2) turns hub (10) and hub (10) turns output shaft (15). Power is sent through the output shaft to the front drive shaft and the transfer gears of the transmission.
One-Way Clutch
Splines connect stator (7) to cam (25). Cam (25) is turned by the stator. Carrier (9) does not turn. The mechanical connection between cam (25) and carrier (9) is rollers (26). Rollers (26) are in openings (24) of cam (25). Springs (23) are also in openings (24). The left side of openings (24) is smaller than the right side of openings (24) because the opening has a taper. Normally, springs (23) keep rollers (26) in the taper at the left side of openings (24).
When the speed of impeller (3) and turbine (2) is slow, stator (7) is held stationary. Rollers (26) are held in the taper of openings (24) by springs (23). There is a mechanical connection between cam (25) and carrier (9). Since carrier (9) is held stationary, cam (25) is held stationary. Since the cam can not turn, the stator does not turn. The stator can send oil back to the impeller.
DETAIL OF ONE-WAY CLUTCH
9. Carrier. 23. Springs. 24. Openings in cam. 25. Cam. 26. Rollers.
As the speed of impeller (3) and turbine (2) increases, stator (7) starts to turn in the same direction as the impeller and turbine. When the stator starts to turn, cam (25) starts to turn. The movement of cam (25) causes rollers (26) to move from the tapers of openings (24). The mechanical connection between cam (25) and carrier (9) is broken. Stator (7) and cam (25) turn freely. The stator does not send oil back to impeller.
Lock-Up Clutch
The lock-up clutch is part of the torque converter and is between the engine flywheel and turbine (2). The lock-up clutch is engaged when the transmission is in SECOND through SEVENTH speeds (direct drive). The lock-up clutch does engage in FIRST speed as the output speed of the transmission increases. When the lock-up clutch is engaged, impeller (3) and turbine (2) turn at the same speed as the engine and there is no loss of power in the torque converter. The connection between the engine and the transmission is now direct.
1. Rotating housing.
2. Turbine.
3. Impeller.
10. Hub.
14. Carrier.
15. Output shaft.
16. Piston.
17. Plate.
18. Inlet passage.
19. Pilot.
20. Discs (two).
21. Plates (two)
22. Passage.
OIL FLOW TO THE LOCK-UP CLUTCH
Rotating housing (1) is connected to the engine flywheel by splines and is fastened to impeller (3) by bolts. Piston (16), plates (21), and plate (17) are also connected to rotating housing (1) by splines. Discs (20) and output shaft (15) are connected to hub (10) by splines. Turbine (2) is fastened to hub (10).
Operation
The pressure of the oil from P1 and governor reduction valve "A" operates the sequence and pressure control valve for operation of the lock-up clutch. Oil from the sequence and pressure control valve goes through inlet passage (18) in the torque converter cover. The oil goes through passage (22) in carrier (14), through the center of output shaft (15), and through pilot (19) and rotating housing (1) to piston (16). The pressure of the oil causes piston (16) to move toward plate (17). This causes discs (20) and plates (21) to be held together and to turn at the same speed. The discs and plates become a direct connection between rotating housing (1) and output shaft (15) and the machine is in direct drive.
When the lock-up clutch is not engaged, the operation of the torque converter is normal.
Direct Drive
1. Rotating housing.
2. Turbine.
3. Impeller.
4. Drive gear for the torque converter and transmission scavenge pump.
7. Stator.
8. One-way clutch.
9. Carrier.
10. Hub.
11. Lock-up clutch.
12. Plate.
13. Hub.
14. Carrier.
15. Output shaft.
FLOW OF POWER IN DIRECT DRIVE
Oil under pressure from the sequence and pressure control valve causes lock-up clutch (11) to engage. See the sections LOCK-UP CLUTCH and SEQUENCE AND PRESSURE CONTROL VALVE FOR THE LOCK-UP CLUTCH.
As the engine flywheel turns, lock-up clutch (11) connects rotating housing (1) with hub (10). This causes turbine (2) and impeller (3) to turn at the same speed and stator (7) to turn freely (freewheel). At this time, the torque converter is not in operation.
The flow of power is from rotating housing (1), through lock-up clutch (11), hub (10) and output shaft (15). The power goes directly through the torque converter, through the front drive shaft, to the transfer gears of the transmission.
Transfer Gears
The transfer gears are in the transfer gear case that is fastened to the front of the transmission case. The front drive shaft connects the torque converter to yoke (3).
Yoke (3) is connected to drive gear (2) by splines. The teeth on drive gear (2) are engaged with the teeth on driven gear (4). Driven gear (4) is connected by splines to the input shaft of the transmission.
Yoke (3) turns drive gear (2) which turns driven gear (4). Driven gear (4) then turns the input shaft of the transmission.
Shims (1) are used to make adjustment to the end play of drive gear (2).
Shims (6) are used to make adjustment to the end play of driven gear (4).
Oil for lubrication of the transfer gears comes from the transmission lubrication circuit. The oil comes through a passage in the transmission case and case (5) into a tube assembly which puts (sprays) oil on both drive gear (2) and driven gear (4). The gears then throw the oil around inside case (5) which provides lubrication for the bearings in the transfer gear case and also the transmission shift governor. The extra oil in the bottom of case (5) goes through a drain passage into the transmission case.
COMPONENTS OF THE TRANSFER GEARS
1. Shims. 2. Drive gear. 3. Yoke. 4. Driven gear. 5. Case. 6. Shims.
Transmission
Power from the engine goes to the torque converter, through the front drive shaft, to the transfer gears which are fastened directly to the front of the transmission case. The power then goes through the planetary transmission and the power take-off drive to the rear drive shaft.
The transmission has seven speeds forward and one reverse. Reverse is torque converter drive only. First speed can have either torque converter drive or direct drive. As ground speed in first speed forward increases, the sequence and pressure control valve for the lock-up clutch gets an indication of output speed of the transmission from the transmission shift governor and engages the lock-up clutch of the torque converter. This gives direct drive to first speed forward. Second through seventh speeds are direct drive only with a short period of converter drive while the clutches engage in the transmission. This makes each shift smooth.
As the transmission shifts either up or down through the forward speeds, the lock-up clutch automatically engages after both of the transmission clutches are engaged. The indication, for transmission to make a shift, comes from the speed of the output shaft of the transmission. These steps then follow:
- 1. Transmission clutch pressure is released as the transmission makes a shift from one forward speed to the next.
- 2. Because the lock-up clutch feels transmission clutch pressure, the release of the transmission clutches controls the operation of the torque converter.
- 3. The transmission clutches are engaged in the next forward speed.
- 4. When the transmission clutches engage, the lock-up clutch engages. The time it takes the oil to engage the lock-up clutch is the delay or sequencing feature in the power train that permits the transmission clutches to engage before the lock-up clutch engages.
- 2. Because the lock-up clutch feels transmission clutch pressure, the release of the transmission clutches controls the operation of the torque converter.
The planetary transmission has disc-type clutches that are hydraulically activated. A manual electric switch in the bottom (base) of the shift console of the cab sends a signal to a slave switch and two solenoids on the transmission case. The slave switch and solenoids control the position of the manual selector spool.
The transmission will automatically make a shift up or down between FIRST speed and any top speed selection the operator has made. For example: If the operator moves the shift lever to FIFTH speed position, the transmission will automatically make shifts between FIRST and FIFTH speeds as the ground speed of the machine changes. Once the operator makes a selection of the top speed, there is no need to move the shift lever until the machine is stopped to go in REVERSE or NEUTRAL.
Each of the seven clutches is made up of more than one clutch disc and plate. Discs (5) and plates (3) are installed so that each second one is the same. Discs (5) have teeth on the inside diameter that engage with the teeth on the outside diameter of gear (4). Plates (3) have notches on the outside diameter that fit around the clutch pins. The clutch pins keep plates (3) from rotation.
CLUTCH OPERATION
1. Piston. 2. Spring. 3. Plates. 4. Gear. 5. Discs. 6. Clutch housing.
The clutches are released by springs (2) which push against clutch housing (6) and piston (1). Oil under pressure behind piston (1) moves the piston toward clutch housing (6). Plates (3) and discs (5) are held together by the force of piston (1). This stops the rotation of discs (5) which stops the rotation of gear (4). This action takes place in all clutches but No. 2 and No. 4 clutches; the rotating clutches. In these clutches, gear (4) and clutch housing (6) turn as a unit when the clutch is engaged.
Transmission Components
1. No. 1 ring gear and carrier.
2. No. 1 outer planetary gears.
3. No. 1 sun gear and No. 2 planetary ring gear.
4. No. 1 planetary ring and coupling gear.
5. No. 2 planetary gears.
6. No. 2 sun gear and No. 3 ring gear.
7. No. 4 ring gear and No. 5 sun gear.
8. No. 5 planetary gears.
9. No. 5 ring gear.
10. No. 6 planetary gears.
11. No. 6 sun gear.
12. No. 7 ring gear.
13. No. 7 inner planetary gears.
14. No. 2 ring gear.
15. Input shaft.
16. No. 6 and No. 7 carrier and output shaft.
17. Center shaft.
18. No. 2 clutch.
19. No. 7 sun gear.
20. No. 7 outer planetary gears.
21. No. 1 clutch.
22. No. 1 inner planetary gears.
23. No. 2 carrier.
24. No. 3 clutch.
25. No. 4 clutch.
26. No. 5 carrier.
27. No. 5 clutch.
28. No. 6 ring and coupling gear.
29. No. 6 clutch.
30. No. 7 clutch.
TRANSMISSION COMPONENTS
The transmission has a combination of seven clutches, five planetary units and two rotating clutches to give seven forward and one reverse speed. No. 2 clutch (18) and No. 4 clutch (25) are the rotating clutches. For the operation of the balance pistons in the rotating clutches see TRANSMISSION LUBRICATION.
The power input and output are on opposite sides of the transmission. Power from the transfer gears goes to input shaft (15) which drives the components of the input section. No. 1 clutch (21) and No. 2 clutch (18) are the clutches in the input section. The remainder of the clutches are in the output section. Center shaft (17) carries the sun gears which drive the output section. Center shaft (17) turns in the same direction as input shaft (15).
NOTE: In each of the illustrations that follow, only the components which have rotation and send power have a darker color. Circles are used to show the engaged clutches.
First Speed
1. No. 1 ring gear and carrier.
2. No. 1 outer planetary gears.
3. No. 1 sun gear and No. 2 planetary ring gears.
4. No. 1 planetary ring and coupling gear.
10. No. 6 planetary gears.
11. No. 6 sun gear.
15. Input shaft.
16. No. 6 and No. 7 carrier and output shaft.
17. Center shaft.
21. No. 1 clutch.
22. No. 1 inner planetary gears.
23. No. 2 carrier.
28. No. 6 ring and coupling gear.
29. No. 6 clutch.
FIRST SPEED (No. 1 and No. 6 Clutches Engaged)
No. 1 clutch (21) and No. 6 clutch (29) are engaged for first speed. No. 1 clutch holds No. 1 ring gear and carrier (1). No. 1 sun gear and No. 2 planetary ring gear (3) on input shaft (15) turns No. 1 inner planetary gears (22) which turns No. 1 outer planetary gears (2). No. 1 planetary ring and coupling gear (4) is driven in the same direction as input shaft (15). No. 2 carrier (23) is connected to No. 1 planetary ring and coupling gear (4) on its outside diameter and center shaft (17) on its inside diameter.
Center shaft (17) turns in the same direction as input shaft (15). No. 6 sun gear (11) turns with center shaft (17). No. 6 clutch (29) holds No. 6 ring and coupling gear (28) which causes No. 6 planetary gears (10) to move around inside No. 6 ring and coupling gear (28). No. 6 and No. 7 carrier and output shaft (16) turns in the same direction as input shaft (15) and power goes to the power take-off drive.
Second Speed
3. No. 1 sun gear and No. 2 planetary ring gear.
4. No. 1 planetary ring and coupling gear.
5. No. 2 planetary gears.
6. No. 2 sun gear and No. 3 ring gear.
10. No. 6 planetary gears.
11. No. 6 sun gear.
15. Input shaft.
16. No. 6 and No. 7 carrier and output shaft.
17. Center shaft.
23. No. 2 carrier.
24. No. 3 clutch.
28. No. 6 ring and coupling gear.
29. No. 6 clutch.
SECOND SPEED (No. 3 and No. 6 Clutches Engaged)
No. 3 clutch (24) and No. 6 clutch (29) are engaged in second speed. With No. 3 clutch (24) engaged, No. 2 sun gear and No. 3 ring gear (6) will not turn. No. 1 sun gear and No. 2 planetary ring gear (3) is driven by input shaft (15) and causes No. 2 planetary gears (5) to move around No. 2 sun gear and No. 3 ring gear (6). This turns No. 2 carrier (23). The power divides between No. 1 planetary ring and coupling gear (4) and No. 2 carrier (23).
Center shaft (17) turns in the same direction as input shaft (15). No. 6 sun gear (11) turns with center shaft (17). No. 6 clutch (29) holds No. 6 ring and coupling gear (28) which causes No. 6 planetary gears (10) to move around inside No. 6 ring and coupling gear (28). No. 6 and No. 7 carrier and output shaft (16) turns in the same direction as input shaft (15) and power goes to the power take-off drive.
Third Speed
1. No. 1 ring gear and carrier.
3. No. 1 sun gear and No. 2 planetary ring gear.
4. No. 1 planetary ring and coupling gear.
10. No. 6 planetary gears.
11. No. 6 sun gear.
14. No. 2 ring gear.
15. Input shaft.
16. No. 6 and No. 7 carrier and output shaft.
17. Center shaft.
18. No. 2 clutch.
28. No. 6 ring and coupling gear.
29. No. 6 clutch.
THIRD SPEED (No. 2 and No. 6 Clutches Engaged)
No. 2 clutch (18) and No. 6 clutch (29) are engaged for third speed. No. 2 clutch (18) holds No. 2 ring gear (14). This causes No. 1 ring gear and carrier (1) to turn. Power is sent through No. 1 planetary ring and coupling gear (4), and No. 1 sun gear and No. 2 planetary ring gear (3), to center shaft (17).
Center shaft (17) turns in the same direction and speed as input shaft (15). No. 6 sun gear (11) turns with center shaft (17). No. 6 clutch (29) holds No. 6 ring and coupling gear (28) which causes No. 6 planetary gears (10) to move around inside No. 6 ring and coupling gear (28). No. 6 and No. 7 carrier and output shaft (16) turns in the same direction as input shaft (15) and power goes to the power take-off drive.
Fourth Speed
3. No. 1 sun gear and No. 2 planetary ring gear.
4. No. 1 planetary ring and coupling gear.
5. No. 2 planetary gears.
6. No. 2 sun gear and No. 3 ring gear.
7. No. 4 ring gear and No. 5 sun gear.
8. No. 5 planetary gears.
9. No. 5 ring gear.
11. No. 6 sun gear.
15. Input shaft.
16. No. 6 and No. 7 carrier and output shaft.
17. Center shaft.
23. No. 2 carrier.
24. No. 3 clutch.
26. No. 5 carrier.
27. No. 5 clutch.
28. No. 6 ring and coupling gear.
FOURTH SPEED (No. 3 and No. 5 Clutches Engaged)
No. 3 clutch (24) and No. 5 clutch (27) are engaged in fourth speed. With No. 3 clutch (24) engaged, No. 2 sun gear and No. 3 ring gear (6) will not turn. No. 1 sun gear and No. 2 planetary ring gear (3) is driven by input shaft (15) and causes No. 2 planetary gears (5) to move around No. 2 sun gear and No. 3 ring gear (6). This turns No. 2 carrier (23). The power divides between No. 1 planetary ring and coupling gear (4) and No. 2 carrier (23).
Center shaft (17), No. 4 ring gear and No. 5 sun gear (7), and No. 6 sun gear (11) turn in the same direction as input shaft (15). No. 5 clutch (27) holds No. 5 ring gear (9). No. 4 ring gear and No. 5 sun gear (7) turns No. 5 planetary gears (8) around inside No. 5 ring gear (9). This causes No. 5 carrier (26) to turn. No. 6 ring and coupling gear (28) turns No. 6 and No. 7 carrier and output shaft (16) in the same direction as input shaft (15). The power is divided between No. 4 ring gear and No. 5 sun gear (7) and No. 6 sun gear (11).
Fifth Speed
1. No. 1 ring gear and carrier.
3. No. 1 sun gear and No. 2 planetary ring gear.
4. No. 1 planetary ring and coupling gear.
7. No. 4 ring gear and No. 5 sun gear.
8. No. 5 planetary gear.
9. No. 5 ring gear.
11. No. 6 sun gear.
14. No. 2 ring gear.
15. Input shaft.
16. No. 6 and No. 7 carrier and output shaft.
17. Center shaft.
18. No. 2 clutch.
26. No. 5 carrier.
27. No. 5 clutch.
28. No. 6 ring and coupling gear.
FIFTH SPEED (No. 2 and No. 5 Clutches Engaged)
No. 2 clutch (18) and No. 5 clutch (27) are engaged for fifth speed. No. 2 clutch (18) holds No. 2 ring gear (14). This causes No. 1 ring gear and carrier (1) to turn. Power is sent through No. 1 planetary ring and coupling gear (4), and No. 1 sun gear and No. 2 planetary ring gear (3), to center shaft (17).
Center shaft (17), No. 4 ring gear and No. 5 sun gear (7), and No. 6 sun gear (11) turn in the same direction as input shaft (15). No. 5 clutch (27) holds No. 5 ring gear (9). No. 4 ring gear and No. 5 sun gear (7) turns No. 5 planetary gears (8) around inside No. 5 ring gear (9). This causes No. 5 carrier (26) to turn. No. 6 ring and coupling gear (28) turns No. 6 and No. 7 carrier and output shaft (16) in the same direction as input shaft (15). The power is divided between No. 4 ring gear and No. 5 sun gear (7) and No. 6 sun gear (11).
Sixth Speed
3. No. 1 sun gear and No. 2 planetary ring gear.
4. No. 1 planetary ring and coupling gear.
5. No. 2 planetary gear.
6. No. 2 sun gear and No. 3 ring gear.
7. No. 4 ring gear and No. 5 sun gear.
11. No. 6 sun gear.
15. Input shaft.
16. No. 6 and No. 7 carrier and output shaft.
17. Center shaft.
23. No. 2 carrier.
24. No. 3 clutch.
25. No. 4 clutch.
26. No. 5 carrier.
28. No. 6 ring and coupling gear.
SIXTH SPEED (No. 3 and No. 4 Clutches Engaged)
No. 3 clutch (24) and No. 4 clutch (25) are engaged in sixth speed. With No. 3 clutch (24) engaged, No. 2 sun gear and No. 3 ring gear (6) will not turn. No. 1 sun gear and No. 2 planetary ring gear (3) is driven by input shaft (15) and causes No. 2 planetary gears (5) to move around No. 2 sun gear and No. 3 ring gear (6). This turns No. 2 carrier (23). The power divides between No. 1 planetary ring and coupling gear (4) and No. 2 carrier (23).
Center shaft (17), No. 4 ring gear and No. 5 sun gear (7) and No. 6 sun gear (11) turn in the same direction as input shaft (15). No. 4 clutch (25) holds No. 4 ring gear and No. 5 sun gear (7) and No. 5 carrier (26) and causes them to turn. Power goes to No. 6 ring and coupling gear (28) and to No. 6 and No. 7 carrier and output shaft (16), which turn in the same direction as input shaft (15). The power is divided between No. 4 ring gear and No. 5 sun gear (7) and No. 6 sun gear (11).
Seventh Speed
1. No. 1 ring gear and carrier.
3. No. 1 sun gear and No. 2 planetary ring gear.
4. No. 1 planetary ring and coupling gear.
7. No. 4 ring gear and No. 5 sun gear.
11. No. 6 sun gear.
14. No. 2 ring gear.
15. Input shaft.
16. No. 6 and No. 7 carrier and output shaft.
17. Center shaft.
18. No. 2 clutch.
25. No. 4 clutch.
26. No. 5 carrier.
28. No. 6 ring and coupling gear.
SEVENTH SPEED (No. 2 and No. 4 Clutches Engaged)
No. 2 clutch (18) and No. 4 clutch (25) are engaged for third speed. No. 2 clutch (18) holds No. 2 ring gear (14). This causes No. 1 ring gear and carrier (1) to turn. Power is sent through No. 1 planetary ring and coupling gear (4), and No. 1 sun gear and No. 2 planetary ring gear (3), to center shaft (17).
Center shaft (17), No. 4 ring gear and No. 5 sun gear (7), and No. 6 sun gear (11) turn in the same direction as input shaft (15). No. 4 clutch (25) holds No. 4 ring gear and No. 5 sun gear (7) and No. 5 carrier (26) and causes them to turn. Power goes to No. 6 ring and coupling gear (28) and to No. 6 and No. 7 carrier and output shaft (16), which turn in the same direction as input shaft (15). The power is divided between No. 4 ring gear and No. 5 sun gear (7) and No. 6 sun gear (11).
The input and output sections turn as a unit at no reduction of speed.
Reverse
1. No. 1 ring gear and carrier.
2. No. 1 outer planetary gear.
3. No. 1 sun gear and No. 2 planetary ring gear.
4. No. 1 planetary ring and coupling gear.
12. No. 7 ring gear.
13. No. 7 inner planetary gear.
15. Input shaft.
16. No. 6 and No. 7 carrier and output shaft.
17. Center shaft.
19. No. 7 sun gear.
20. No. 7 outer planetary gear.
21. No. 1 clutch.
22. No. 1 inner planetary gear.
23. No. 2 carrier.
30. No. 7 clutch.
REVERSE (No. 1 and No. 7 Clutches Engaged)
No. 1 clutch (21) and No. 7 clutch (30) are engaged for reverse. No. 1 clutch holds No. 1 ring gear and carrier (1). No. 1 sun gear and No. 2 planetary ring gear (3) on input shaft (15) turns No. 1 inner planetary gears (22) which turns No. 1 outer planetary gears (2). No. 1 planetary ring and coupling gear (4) is driven in the same direction as input shaft (15). No. 2 carrier (23) is connected to No. 1 planetary ring and coupling gear (4) on its outside diameter and center shaft (17) on its inside diameter.
Center shaft (17) and No. 7 sun gear (19) turn in the same direction as input shaft (15). No. 7 clutch (30) holds No. 7 ring gear (12) from rotation. No. 7 sun gear (19) turns No. 7 inner planetary gear (13) which causes No. 7 outer planetary gears (20) to move around No. 7 ring gear (12). This causes No. 6 and No. 7 carrier and output shaft (16) to turn in the opposite direction of input shaft (15).
Transmission Lubrication
1. Passage (input).
2. Passage.
3. Passage (output).
4. Balance piston for No. 4 clutch.
5. Passage.
6. Passage.
7. Passage.
8. Passage.
9. Passage.
10. Balance and clutch piston for No. 2 clutch.
11. Passage.
12. Passage.
TRANSMISSION LUBRICATION
Oil for lubrication of the transmission is provided by the flow control valve of the pressure control valve in the transmission hydraulic controls. Oil from the flow control valve goes down to the accumulator group in the bottom of the transmission hydraulic controls. The accumulator group divides the flow of the oil.
Part of the oil goes through a passage in the transmission case to passage (1) for lubrication of the front (input section) of the transmission.
The remainder of the oil goes through a tube, to the brake control valve, back through a tube, to the accumulator group, and into passage (3) for lubrication of the rear (output section) of the transmission.
The oil in passage (1) goes through passage (2) for lubrication of No. 1 carrier. Oil for the balance operation of balance and clutch piston (10) comes from passage (9). This oil then goes to passage (7) for lubrication of No. 2 and No. 1 clutches.
The oil in passage (3) goes several different places. It goes through drilled passages to No. 3 clutch and to balance piston (4). The oil also goes through drilled passages to the center shaft. The oil goes around the outside of the center shaft to provide lubrication of bearings, No. 4 clutch, and No. 3 and No. 4 carriers. In No. 4 carrier, oil flows from passage (6), through the carrier, to passage (8) for lubrication of the outer planetary gears.
Oil also goes into passage (5) of the center shaft. This oil is for lubrication of the input and center shaft bearings and for No. 2 carrier.
Oil from passage (3) also goes into passage (11). This oil provides lubrication for No. 5, No. 6, and No. 7 clutches. It also goes to passage (12) for lubrication of the power take-off drive of the transmission.
Operation of the Balance Pistons in the Rotating Clutches
The oil that goes to balance piston (4) for No. 4 clutch and balance and clutch piston (10) for No. 2 clutch is used to balance the force of the oil (centrifugal force) caused by the rotation of No. 2 and No. 4 clutches. The centrifugal force of the oil behind the clutch piston in the rotating clutches causes a small amount of clutch engagement (clutch drag) in the rotating clutch. The centrifugal force of the oil behind the balance piston balances or removes the centrifugal force of the oil on the clutch piston.
Power Take-Off Drive For The Transmission
COMPONENTS OF THE POWER TAKE-OFF DRIVE
1. No. 7 clutch housing of the transmission. 2. Cage. 3. Retainer. 4. No. 6 and No. 7 carrier and output shaft of the transmission. 5. Retainer. 6. Shims. 7. Yoke assembly. 8. Passage for lubrication. 9. Bearing assembly.
The power take-off (PTO) drive is fastened directly to the output section of the transmission. It is the connection between No. 6 and No. 7 carrier and output shaft (4) of the transmission and the rear drive shaft which is connected to the differential.
Yoke assembly (7) is connected to No. 6 and No. 7 carrier and output shaft (4) by splines. The rear drive shaft is connected directly to yoke assembly (7). Cage (2) is fastened to No. 7 clutch housing (1).
Retainer (3) keeps the cup of bearing assembly (9) from rotation in cage (2). Retainer (5) holds the cones and spacer of bearing assembly (9) in position. Without the installation of shims (6), retainer (5) will bend.
Passage (8) in cage (2) sends oil from the transmission lubrication system to bearing assembly (9).
Transmission Electrical Controls
WIRING DIAGRAM OF THE MANUAL (CONSOLE) SWITCH AND CAB HARNESS (NEUTRAL POSITION)
The batteries and charging alternator give the electric power needed to control operation of the transmission. The electrical switch group causes the transmission to shift and has control of each shift. A manual switch, controlled by the operator, activates the solenoids on the transmission. It must be remembered here that the switch gives the transmission automatic controls the ability to shift. Governor rpm controls when a shift is to be made.
The manual switch in the shift console of the cab is a three-section switch. The sections make contact by rotation movement with the terminal manually selected. The manual switch controls the back-up alarm and back-up light. The switch lets current go to the light circuit and back-up alarm when the transmission selector lever is in the REVERSE position.
LOCATION OF MANUAL SWITCH
1. Manual switch (inside console).
The transmission selector lever must be in NEUTRAL when the engine is started. The rotor of the manual switch is connected to the transmission selector lever so the arm of the rotating assembly will be on the neutral contact when the engine is started.
The operator has only the FIRST, NEUTRAL and REVERSE speeds under his direct control. Governor rpm has control of the other shifts. The operator controls the speed with the manual switch.
For example: If the operator does not want to go beyond FOURTH speed, he moves the manual switch to 4. When the transmission moves to FOURTH speed, the circuit to the shift solenoid is closed even though the governor rpm would permit further shifts. The transmission does not make a shift beyond the selection made by the operator.
The slave switch is fastened to the case of the transmission. The slave switch has three downshift switches and three upshift switches. Rotors on each of the switches are connected to a shaft in the switch. A gear is connected to the shaft. The teeth of the gear are engaged with teeth on the shift cam of the hydraulic controls for the transmission. When the transmission makes a shift, the shift cam moves and turns the gear. The gear turns the shaft which turns the rotors of the switch. As the rotors turn, they make contact with the terminals of the switches.
WIRING DIAGRAM OF THE SLAVE (TRANSMISSION)
SWITCH AND CHASSIS HARNESS (NEUTRAL POSITION)
The manual switch has a terminal for each speed forward, one each for NEUTRAL and REVERSE. There are also terminals for back-up alarm power, back-up alarm relay and battery voltage.
The first upshift switch of the slave switch has ten terminals, one for each speed forward and one each for NEUTRAL and UPSHIFT. Terminal 1 is not used in this application.
The second upshift switch has seven terminals, one each for SECOND through SEVENTH speeds and one for UPSHIFT.
The third upshift switch has four terminals, one each for FIFTH, SIXTH, SEVENTH and UPSHIFT.
LOCATION OF SLAVE SWITCH
2. Slave switch (inside cover).
The first downshift switch has four terminals one each for NEUTRAL, REVERSE and DOWNSHIFT. Terminal 1 is not used in this application.
The second downshift switch has seven terminals, one each for FIRST through THIRD and one each for NEUTRAL, REVERSE and DOWNSHIFT. Terminal 1 is not used in this application.
The third downshift switch has ten terminals, one each for FIRST through SIXTH and one each for NEUTRAL, REVERSE and DOWNSHIFT. Terminal 1 is not used in this application.
LOCATION OF SHIFT SOLENOIDS
3. Upshift solenoid. 4. Downshift solenoid.
Upshifts
When the transmission selector lever is in NEUTRAL the rotor of the manual switch is in contact with terminal N on the manual switch. When the electrical circuit is activated, a voltage will be sent from terminal N of the manual switch to the four terminals N of the slave switch. If the transmission controls are in NEUTRAL, none of the four terminals N will make contact with the slave switch rotors.
If the transmission controls are not in NEUTRAL, one of the four terminals will make contact with a rotor which is connected to either an UPSHIFT or DOWNSHIFT solenoid. Three of the four terminals N can make contact with rotors connected to the DOWNSHIFT solenoid and one terminal N can make contact with a rotor connected to the UPSHIFT solenoid.
For example: If the transmission controls are in REVERSE and the manual switch is in NEUTRAL, the rotor connected to the UPSHIFT solenoid will be in contact with terminal N of the slave switch. The electrical current activates the UPSHIFT solenoid. The UPSHIFT solenoid opens a passage which lets pressure oil behind the shift cylinder spool. The shift cylinder spool moves to the right to shift the transmission controls to NEUTRAL. When the transmission controls move to NEUTRAL, the shift cam moves inside the transmission case. The shift cam turns the gear of the slave switch. As the gear turns, it turns the rotors of the slave switch. When the transmission controls have moved to NEUTRAL, the rotor of the slave switch does not make contact with terminal N. The electric current to the UPSHIFT solenoid is stopped and the solenoid closes (deactivates). This stops the flow of pressure oil to the shift cylinder spool.
Shift From Neutral To First
With both the transmission selector lever and transmission in NEUTRAL, the transmission selector lever is moved to FIRST. This moves the manual switch rotor to make a circuit from battery voltage to terminal 1 of the manual switch. Battery voltage is sent from terminal 1 of the manual switch to the three SECOND speed terminals of the slave switch.
NOTE: TERMINALS 1 ON THE SLAVE SWITCH ARE NOT USED.
Terminal 2 of the upshift portion of the slave switch makes a connection through the rotor to the UPSHIFT solenoid. The activated UPSHIFT solenoid opens a passage which lets pressure oil behind the shift cylinder spool. The shift cylinder spool moves the transmission controls to FIRST. Because terminal 1 is not used on the slave switch, the shift cylinder spool must move the equivalent of two positions. When the shift cylinder spool moves, the manual selector spool and the shift cam move inside the transmission case. The shift cam turns the gear of the slave switch. As the gear turns, it turns the rotors of the slave switch past terminals 1 and 2, to terminal 3. As the rotor moves beyond terminal 2, the electrical current is stopped between terminal 2 and the UPSHIFT solenoid. The UPSHIFT solenoid deactivates, which stops pressure oil to the shift cylinder spool. The pressure oil behind the shift cylinder spool is permitted to drain into the transmission case.
Since terminal 3 of the upshift switch is closed, the slave switch is ready for the next upshift. The rotor of the first downshift switch is in contact with terminal N. The slave switch is now also ready for the next downshift.
All upshifts follow the same sequence of operation. The only difference is that each upshift uses different terminals of the switches. After an upshift is complete, the upshift switches ready for the next upshift and the downshift switches are ready for the next lower downshift.
Downshifts
When the transmission selector lever is in FIRST speed position the rotor of the manual switch is in contact with terminal 1 of the switch. Terminal 1 is now open and terminal N is closed.
The electric current from terminal N of the manual switch goes to terminals N of the upshift and downshift switches. Terminal N of the upshift switch is open. Terminal N of the first downshift switch is closed.
The electric current goes through terminal N of the downshift switch to the downshift solenoid. The electric current activates downshift solenoid. The downshift solenoid opens a passage which lets pressure oil go to the right end of the shift cylinder spool. The pressure of the oil moves the shift cylinder spool back to the left to the NEUTRAL position. The movement of the shift cylinder spool moves the linkage of the hydraulic controls. The transmission makes the shift to NEUTRAL.
When the transmission makes the shift to NEUTRAL, the shift cam moves. The shift cam turns the gear of the slave switch. The gear turns the rotors of the switches.
The rotor of the first downshift switch is now in contact with terminal R. Terminal N is open. The electric current to the downshift solenoid is stopped. The pressure oil at the right end of the shift cylinder spool goes to the reservoir. The movement of the shift cylinder spool is stopped.
The rotor of the upshift switch is now in contact with terminal 2. Terminal N is open. Terminal 2 is closed. The upshift switch is now ready for the next upshift.
All downshifts follow the same sequence of operation. The only difference is that each downshift uses different terminals of the switches. After a downshift is complete, downshift switches are ready for the next downshift and upshift switches are ready for the next higher upshift.
Transmission Hydraulic Controls
1. Shift cylinder group.
2. Accumulator group for the governor.
3. Governor cut-off valve.
4. Cover.
5. Automatic selector valve.
6. Shift pressure valve.
7. Pressure control valve.
8. Slave switch.
9. Selector valve.
10. Accumulator group for No. 6 clutch.
TRANSMISSION HYDRAULIC CONTROLS
The transmission hydraulic controls send oil to operate the transmission and torque converter. The inlet and outlet relief valves of the torque converter are fastened to the torque converter cover. The sequence and pressure control valve for the torque converter and shift cylinder group (1) are fastened to cover (4) of the transmission case.
The automatic shift group is made up of the shift governor, accumulator group (2) for the governor, governor cut-off valve (3), automatic selector valve (5) and shift pressure valve (6). The shift governor is fastened to the front of the transfer gear case. The remainder of the valves in this group are fastened directly to the pressure and selector valve group.
The pressure and selector valve group is made up of pressure control valve (7), selector valve (9), and accumulator group (10) for No. 6 clutch. This group is fastened directly to the No. 4 clutch housing inside the transmission case.
Shifts into REVERESE, NEUTRAL and FIRST are activated manually by the operator. Other upshifts and downshifts are automatic.
REVERSE and FIRST are driven by the torque converter. In other speeds, the hydraulic controls hold the converter in direct drive.
Inlet And Outlet Relief Valves For The Torque Converter
LOCATION OF THE RELIEF VALVES
1. Inlet relief valve. 2. Outlet relief valve.
Inlet relief valve (1) and outlet relief valve (2) are fastened to the torque converter cover. The valves are for the torque converter only.
Oil, from the torque converter side of the oil pump for the transmission and torque converter, goes through the torque converter oil filter on its way to the torque converter.
Inlet relief valve (1) controls the maximum pressure of the oil to the torque converter. The setting of the inlet relief valve is 135 psi (930 kPa). Extra oil from inlet relief valve (1) goes back to the hydraulic tank through outlet passage (5).
| NOTICE |
|---|
Inlet pressure to the torque converter MUST NOT be over 135 psi (930 kPa) with COLD OIL. Pressures greater than the maximum setting will result in damage to the torque converter. |
COMPONENTS OF THE RELIEF VALVES
3. Body. 4. Inlet passage. 5. Outlet passage. 6. Poppet valve. 7. Valve spool. 8. Shims. 9. Spring.
Outlet relief valve (2) controls the maximum pressure in the torque converter. The setting of the outlet relief valve is about 60 psi (415 kPa). From outlet relief valve (2), the oil goes through outlet passage (5) to the brake and torque converter oil cooler.
The operation of both valves is the same. Oil goes into body (3) through inlet passage (4). The oil goes through a hole in valve spool (7) into the chamber between poppet valve (6) and valve spool (7). The oil moves valve spool (7) against the force of spring (9) when the pressure of the oil becomes greater than the force of the spring. The movement of valve spool (7) permits the oil to flow through outlet passage (5).
Sequence And Pressure Control Valve For The Lock-Up Clutch
LOCATION OF THE SEQUENCE AND PRESSURE CONTROL VALVE
1. Sequence and pressure control valve. 2. Line to lock-up clutch. 3. Line from the pump. 4. Line from governor reduction valve "A". 5. Line from shuttle valve. 6. Line to shift cylinder.
7. Valve body.
8. Passage from the pump.
9. Reduction valve.
10. Passage from shuttle valve.
11. Load piston.
12. Passage not open (blocked by transmission cover).
13. Passage from governor reduction valve "A".
14. Slug.
15. Passage to drain.
16. Passage to the lock-up clutch.
17. Passage to the shift cylinder.
18. Passage to drain.
19. Lock-up clutch selector valve.
20. Screw for adjustment of pressure.
COMPONENTS OF THE SEQUENCE AND PRESSURE CONTROL VALVE
The lock-up clutch of the torque converter is engaged by oil, with pressure, that comes from sequence and pressure control valve (1). The valve is fastened to the left side of the cover for the transmission case.
Oil from the transmission pump goes through passage (8) to reduction valve (9). Reduction valve (9) controls the pressure of the oil for the correct operation of the shift cylinder and lock-up clutch [approximately 160 psi (1100 kPa)]. Oil goes around lock-up clutch selector valve (19) through passage (17) to provide oil for the shift cylinder.
When P1 pressure increases, the increase in pressure is felt through passage (10) on load piston (11). This increase in pressure causes load piston (11) and lock-up clutch selector valve (19) to start to move to the right. The movement of load piston (11) causes oil line (13) from governor reduction valve "A" to become open. The oil from governor reduction valve "A" causes slug (14) and selector valve (19) to move to the right. Slug (14) moves slowly at first since its orifice is still open to drain. As soon as the orifice is closed, slug (14) moves lock-up clutch selector valve (19) immediately all the way to the right.
The movement of lock-up clutch selector valve (19) lets oil from passage (8) go through passage (16) to engage the lock-up clutch of the torque converter. The torque converter is now in direct drive (the turbine and impeller are "locked" together and turn as a unit). The power of the engine goes directly from the flywheel to the transfer gears of the transmission.
When a shift is made and the pressure in P1 and governor reduction valve "A" decreases, load piston (11) and lock-up clutch selector valve (19) move to the left. Lock-up clutch selector valve (19) stops the flow of oil to the lock-up clutch and the torque converter operates. This makes the shifts smooth. When the pressure increases at passage (10), load piston (11) and lock-up clutch selector valve (19) again move to the right and the lock-up clutch is engaged again.
Shift Cylinder Group
SHIFT CYLINDER GROUP
1. Shift cylinder body. 2. Inlet passage from the sequence and pressure control valve. 3. Passage to reservoir (drain). 4. Shift spool. 5. Passage from solenoid to spool. 6. Passage from solenoid to spool. 7. Downshift solenoid. 8. Upshift solenoid. 9. Tubes (two for drain.
Shift spool (4) controls the movement of manual selector spool. Current activates the solenoids in the shift cylinder group which permits oil to flow into passage (5) or (6). The pressure of the oil in these passages moves shift spool (4) either to the right for an upshift or to the left for a downshift.
Shift Governor
The shift governor is inside the transfer gear case. The governor drive is connected to the output shaft of the transmission by a shaft that goes through the center of the shafts of the transmission. The governor drive shaft turns drive gear (1) which turns idler gear (2). Idler gear (2) turns the governor. The governor turns only when the output shaft of the transmission turns.
The governor has three valves inside the governor housing. Each valve has a different weight and oil chamber size. As the rpm of the output shaft becomes higher, the valves move away from governor shaft (3). As the rpm of the output shaft becomes lower, the valves move back toward governor shaft (3). Since each valve has a different size and weight, the valves move at different rpms of the output shaft. As each valve moves out, the outlet opening becomes larger which causes an increase in pressure in the outlet passage.
GOVERNOR SHAFT
1. Drive gear. 2. Idler gear. 3. Governor shaft. 4. Inlet groove. 5. Outlet groove. 6. Outlet groove. 7. Outlet groove.
The governor has four grooves. Inlet groove (4) lets oil, from the downshift reduction valve, into governor housing (8). Outlet grooves (5), (6) and (7) send oil from the governor reduction valves to the governor cut-off valve and on to the inner ends of the automatic selector spools.
SHIFT GOVERNOR
8. Governor housing. 9. Governor reduction valve "C" (fifth to sixth, sixth to seventh speed upshift and seventh to sixth, sixth to fifth speed downshifts). 10. Inlet chamber from downshift reduction valve. 11. Outlet chamber to automatic selector spool. 12. Outlet chamber to automatic selector spool. 13. Inlet chamber from downshift reduction valve. 14. Governor reduction valve "B" (third to fourth, fourth to fifth speed upshifts and fifth to fourth, fourth to third speed downshifts). 15. Governor reduction valve "A" (first to second, second to third speed upshifts and third to second, second to first speed down-shifts). 16. Inlet passage from downshift reduction valve. 17. Outlet chamber to automatic selector spool.
As the machine begins to move, the governor begins to turn. Centrifugal force moves the governor reduction valves away from governor shaft (3). As each valve moves away, it starts to open a passage to let pressure oil go to the inner ends of the automatic selector spools. This causes an increase in the pressure of the oil. The higher pressure oil goes through an orifice in each reduction valve. The oil fills the outer chamber in each reduction valve. The pressure of the oil in the outer chambers moves each reduction valve toward governor shaft (3). This stops the flow of the oil from the reduction valves to the automatic selector spools. The pressure of the oil in each outer chamber is against the centrifugal force that moves the reduction valves away from the governor shaft.
The difference in weight and size of the chamber for each of the reduction valves causes different pressures for each governor oil line. Each governor reduction valve moves at a different governor speed.
Since the rpm of the output shaft controls the ground speed of the machine, as the machine goes faster the governor causes upshifts As the machine goes slower, the governor causes downshifts.
Governor Cut-Off Valve
The governor cut-off valve is the top cover and manifold of the hydraulic controls. During shifts, the speed of the governor drive shaft is variable and can cause the transmission to make rapid shifts that are not wanted. The governor cut-off valve holds the governor outlet pressures in the automatic selector valve between shifts of the transmission. Spool (1) stops the flow of oil from governor reduction valves "A", "B" and "C" to the automatic selector spools during shifts. This movement of spool (1) will not let the hydraulic controls go rapidly from one speed to another (transmission hunts).
GOVERNOR CUT-OFF VALVE
1. Spool. 2. Spring. 3. Passage. 4. Passages (three). 5. Passage.
Spool (1) is held open by P1 pressure in passage (5). Oil pressure from the downshift reduction valve [about 100 psi (690 kPa)] is in passage (3). When a shift is made, P1 pressure decreases. This permits the pressure in passage (3) and the force of spring (2) to move spool (1). The movement of spool (1) closes passages (4) from the governor reduction valves. This stops the flow of signal oil from the governor to the automatic selector spools. This action prevents shifts that are not wanted and gives a delay in time which lets the clutches go to the full pressure between each shift of the transmission, both up and down.
Accumulator Group For The Governor
The accumulator group for the governor is fastened directly to the transmission case. It is connected by sleeves to the governor cut-off valve. The purpose of this accumulator group is to keep the pressures from governor reduction valves "A" and "B" constant in the 80 to 90 psi (550 to 620 kPa) range.
ACCUMULATOR GROUP FOR THE GOVERNOR
1. Passage from downshift reduction valve to governor. 2. Accumulator for oil from reduction valve "A". 3. Accumulator for oil from reduction valve "B". 4. Passage from reduction valve "C" to governor cut-off valve. 5. Passage from reduction valve "A" to accumulator (2) and governor cut-off valve. 6. Passage from reduction valve "B" to accumulator (3) and governor cut-off valve.
Automatic Selector Valve
1. Passage from oil filter.
2. Manual selector spool.
3. Passage from downshift reduction valve.
4. Passage from downshift reduction valve.
5. Hydraulic shift spool.
6. Passage from governor reduction valve "A".
7. Passage from governor reduction valve "C".
8. Passage from upshift reduction valve-low.
9. Passage from upshift reduction valve-high.
10. Passage from upshift reduction valve-medium.
11. Passage from governor reduction valve "B".
12. Hold slugs (six).
13. Passage to reservoir.
14. Automatic selector spools (six).
15. Downshift slugs (six).
AUTOMATIC SELECTOR VALVE
The automatic selector valve is directly below the governor cut-off valve. This valve has a manual selector spool (2), hydraulic shift spool (5), and six automatic selector spools (14) with six hold slugs (12) and six downshift slugs (15).
Passages inside the valve body connect the spools together. Passages R and N at manual selector spool (2) are connected to the same passages at hydraulic shift spool (5) for a shift to REVERSE or NEUTRAL. Passages 1H through 6H at manual selector spool (2) are connected to the same passages at automatic selector spools (14). These passages are for the operation of hold slugs (12). Passages 1 through 7 at hydraulic shift spool (5) are connected to the same passages at automatic selector spools (14). These passages are used to make a shift to FIRST through SEVENTH speeds.
Manual Selector Spool
Manual selector spool (2) is connected by linkage to the shift cylinder group. The position of the transmission selector lever directly controls the position of the manual selector spool. Manual selector spool (2) controls REVERSE, NEUTRAL and FIRST speeds and also prevents upshifts of the transmission higher than the position of the transmission selector lever. The rest of the speed ranges are automatic.
Each time manual selector spool (2) moves to the right, it drains one passage of an automatic selector spool. Each time the spool moves to the left, it lets oil under pressure go to an automatic selector spool (closes the drain).
Movement of manual selector spool (2) to REVERSE or NEUTRAL opens passage R or N to the reservoir. Oil goes from passage R or N out through the passage in the end of manual selector spool (2). This causes oil pressure in passage (3) or (4) to decrease and causes hydraulic shift spool (5) to move. The hydraulic shift spool closes passage R or N and also moves the selector spools in the selector valve and causes the transmission to make a shift into either REVERSE or NEUTRAL.
Any movement of manual selector spool (2) to FIRST speed or higher puts the hydraulic controls in the automatic range. This opens passage (1) and permits oil, under a pressure of approximately 460 psi (3170 kPa) minimum, to flow to passages 1H through 6H. The oil in passages 1H through 6H goes to the respective passages at each automatic selector spool (14). The oil goes into the automatic selector spools and pushes the spools to the inside and hold slugs (12) to the outside of the valve body. Automatic selector spools (14) are now held in position by hold slugs (12). When the automatic selector spools are held to the inside, there is no automatic shift to a speed higher than the position of manual selector spool (2). Each time the manual selector spool is moved to the next higher speed, the oil pressure at a hold slug is permitted to go out through passage (13) to the reservoir. Now, the automatic selector spool for that speed is not held to the inside and the transmission can make an upshift.
Each time the transmission selector lever is moved to the next higher speed, manual selector spool (2) opens another hold passage to passage (13). When the pressure from the governor reduction valve becomes higher than the pressure from the upshift reduction valve, the controls are in a position to make the next speed available.
Hydraulic Shift Spool
Hydraulic shift spool (5) is connected by linkage to the selector valve. Hydraulic force moves the spool and causes the transmission to make a shift in both manual and automatic speeds.
Both ends of the land of hydraulic shift spool (5) are open to oil under pressure from the downshift reduction valve. When any of passages R, N, and 1 through 7 are open to passage (13), there is a difference in pressures between passages (3) and (4). Hydraulic shift spool (5) moves until the land is over the open passage. The pressure of the oil on both sides of the land [in passages (3) and (4)] is the same and the hydraulic shift spool is held in this position.
Movement of hydraulic shift spool (5) moves the selector spools in the selector valve and causes the transmission to shift to the next speed.
Automatic Selector Spools, Hold Slugs and Downshift Slugs
Automatic selector spools (14) "tell" hydraulic shift spool (5) when to make a shift. The automatic selector spools get constant "reference" pressure from the upshift reduction valves of the shift pressure valve. The "reference" pressures from the upshift reduction valves make a balance with the pressures from the governor reduction valves. Upshifts and downshifts are automatic when automatic selector spools (14) open and/or close the openings to the hydraulic shift spool.
Hold slugs (12) at the outside end of each automatic selector spool keep the spools from movement. The hold slugs prevent an automatic upshift to a speed higher than the position of the transmission selector lever. Hold slugs (12) also prevent a manual downshift when the speed of the machine is too fast.
Pump pressure of approximately 460 psi (3170 kPa) is in the passages at hold slugs (12). This high pressure holds automatic selector spools (14) in the downshift position.
Downshift slugs (15) at the inner end of each automatic selector spool get pressures from the shift governor. The downshift slugs are different sizes to permit automatic selector spools (14) to move at different pressures. Downshift slugs (15) do not move.
Shift Pressure Valve
1. Poppet valve.
2. Priority valve.
3. Downshift reduction valve.
4. Passage from oil filter.
5. Passage to governor.
6. Hold valve.
7. Passage for air.
8. Passage to reservoir.
9. Passage to selector and pressure control valves.
10. Passage to hydraulic shift spool.
11. Upshift reduction valve (first to second speed upshift).
12. Passage to automatic selector valve (low reference pressure).
13. Upshift reduction valve (second to third, fourth to fifth and sixth to seventh speed upshifts).
14. Passage to automatic selector valve (high reference pressure).
15. Upshift reduction valve (third to fourth and fifth to sixth speed upshifts).
16. Passage to automatic selector valve (medium reference pressure).
SHIFT PRESSURE VALVE
The shift pressure valve has a priority valve (2), downshift reduction valve (3), hold valve (6), and three upshift reduction valves (11), (13) and (15).
Adjustment of all of the valves in the shift pressure valve, except hold valve (6), can be done by screws. These screws can be reached through the transmission case.
Priority Valve
Priority valve (2) makes sure that the oil pressure to downshift reduction valve (3) is approximately 460 psi (3170 kPa) before oil goes to the remainder of the system. Some of this oil is also used to release the parking brake. Oil under high pressure is needed to release the brake. When the pressure gets above 460 psi (3170 kPa), the priority valve opens and lets oil go to the selector and pressure control valves.
Transmission Hydraulic Controls
Poppet valve (1) controls the movement of priority valve (2). When the oil pressure in the chamber between the priority valve and the poppet valve becomes high enough, it pushes poppet valve (1) off of its seat. This releases the pressure of the oil in the chamber and permits priority valve (2) to move against the force of its spring. This lets the oil flow out passage (9) to the selector and pressure control valves. The action of poppet valve (1) causes the priority valve to release the oil pressure gradually and smoothly.
The adjustment screw on the end of poppet valve (1) can be turned to increase or decrease the pressure of priority valve (2).
Downshift Reduction Valve
Downshift reduction valve (3) gets oil from the oil filter through passage (4). It sends the oil at approximately 100 psi (690 kPa) to the governor, reduction valves, hydraulic shift spool, and upshift reduction valves (11), (13), and (15). The valve also controls when the transmission is to downshift. Adjustment of downshift reduction valve (3) has an effect on the downshift points of the transmission.
Hold Valve
Hold valve (6) is operated by air. When the valve is activated it stops the supply of oil to the hydraulic shift spool. The purpose of the valve is to stop the flow of oil to the hydraulic shift spool so the transmission can be shifted manually, for test purposes.
Upshift Reduction Valves
Upshift reduction valves (11), (13) and (15) send reference pressure oil to the automatic selector spools in the automatic selector valve. The pressures in passages (12), (14) and (16) work against (opposite) the pressures from the governor reduction valves at the automatic selector spools. Adjustment of the upshift reduction valves has an effect on the upshift points of the transmission.
Upshift reduction valve (11) makes reference pressure available for the automatic upshift from first to second speeds.
Upshift reduction valve (13) makes reference pressure available for the automatic upshift of the speeds that follow: second to third, fourth to fifth and sixth to seventh.
Upshift reduction valve (15) makes reference pressure available for the automatic upshift for third to fourth speeds and fifth to sixth speeds.
Pressure Control Valve
1. Flow control valve.
2. Outlet passage for transmission lubrication.
3. Inlet passage from priority valve (pump pressure).
4. Check valve.
5. Orifice.
6. Check valve.
7. Inlet passage from priority valve (P1 pressure).
8. Load piston relief valve.
9. Modulation relief valve.
10. Inlet passage from selector valve (pump pressure).
11. Load piston.
12. Protective valve.
13. Outlet passage to selector valve.
14. Orifice.
15. Inlet passage from No. 1 clutch.
PRESSURE CONTROL VALVE
The pressure control valve is between the shift pressure valve and the selector valve in the hydraulic controls. It is made up of six valves and a load piston. The chart that follows give the operation of each valve.
Flow Control Valve
At the pressure control valve, the oil divides into separate circuits. Part of the flow goes through an orifice at passage (7) to the left end of flow control valve (1). Some of the oil also goes through inlet passage (3). The orifice and flow control valve (1) make sure that there is 15 U.S. gpm (57 litre/min) to fill the clutches of the transmission. There is a change of approximately 40 psi (280 kPa) from one side of the orifice to the other when oil flow through the orifice is 15 U.S. gpm (57 litre/min).
When the flow is more than 15 U.S. gpm (57 litre/min), the oil from inlet passage (3) pushes flow control valve (1) to the left. This lets the remainder of the oil go through outlet passage (2) for transmission lubrication.
Some of the oil from passage (7) goes through an orifice in flow control valve (1). The pressure of this oil (P1 pressure) and the force of the spring in flow control valve (1) work against pump pressure from inlet passage (3) which causes flow control valve (1) to open.
Modulation Relief Valve
Modulation relief valve (9) controls the maximum amount of oil pressure in the clutches of the transmission.
The oil from inlet passage (7) goes around flow control valve (1) to modulation relief valve (9). The oil goes through an orifice in modulation relief valve (9). When the pressure of the oil gets to approximately 410 psi (2820 kPa) in converter drive and 300 psi (2050 kPa) in direct drive, the modulation relief valve is pushed to the right. The extra oil from modulation relief valve (9) goes to the transmission for lubrication.
Protective Valve
Protective valve (11) will not permit movement of the machine if the engine is started with the transmission selector lever out of NEUTRAL position.
The oil from the priority valve divides at the pressure control valve. The oil that is not used by the pressure control valve goes to the selector valve. Passages inside the body of the selector valve send oil back to the pressure control valve through inlet passage (10).
When the machine is started in NEUTRAL, the oil from inlet passage (10) goes through protective valve (12) and pushes it to the right. The oil from modulation relief valve (1) is now permitted to flow past the protective valve to the remainder of the pressure control valve and also to the clutches.
When the machine is started in any speed except NEUTRAL, one of the selector spools in the selector valve stops the flow of oil to inlet passage (10). Protective valve (12) does not move to the right. The oil from modulation relief valve (9) goes to the protective valve and stops. The clutches can not fill with oil when the protective valve is in this position.
Load Piston
Load piston (11) controls the rate of increase in pressure of modulation relief valve (9). The oil from protective valve (12) goes through a passage to orifice (14) and on to load piston (11). When No. 1 clutch is used, oil also comes through inlet passage (15), orifice (5), and check valve (6).
As the pressure of the oil increases behind load piston (11), it causes it to move to the left. This also causes modulation relief valve (9) to move to the left. This stops the flow of oil to outlet passage (2) and causes the pressure of the oil to increase. This again causes modulation relief valve (9) to move to the right. The increase in pressure will also cause load piston (11) to again move to the left. This again causes modulation relief valve (9) to move to the left and the pressure again increases. This cycle takes place again and again until maximum pressure is reached.
Orifice (14) and orifice (5), when used, cause a delay to the increase in pressure at load piston (11). This gradual increase in pressure caused by the load piston, at modulation relief valve (9) is called modulation.
Check Valve (4)
Check valve (4) permits the oil behind load piston (11) to go to the reservoir when the pressure in the system decreases. The movement of check valve (4) makes sure that load piston (11) goes back to its original position when a clutch starts to fill and engage. The force of the springs on load piston (11) will cause check valve (4) to move to the left against the force of its spring.
When the pressure in the system increases, the spring and the pressure of oil will cause check valve (4) to move to the right. This closes the drain passage and permits the pressure to increase at load piston (11).
Check Valve (6)
Check valve (6) will not let oil go from load piston (11) through orifice (5) when No. 1 clutch is not engaged.
When No. 1 clutch is used, check valve (6) permits oil flow through orifice (5) to help fill the load piston chamber.
Load Piston Relief Valve
Load piston relief valve (8) has a lower setting than modulation relief valve (9). This relief valve controls the maximum pressure at load piston (11) when the transmission is in direct drive.
When No. 1 clutch is used (when the transmission is in converter drive), oil from No. 1 clutch goes through inlet passage (15) to the left side of load piston relief valve (8). This oil holds the relief valve to the right and will not permit it to operate. The oil then goes through orifice (5) and check valve (6) to load piston (11). The pressure in the system will go to its maximum [the setting of modulation relief valve (9)] for normal operation of the torque converter in REVERSE and FIRST speeds.
When No. 1 clutch is not used, load piston relief valve (8) will operate. As the pressure at load piston (11) increases, the pressure is felt on the relief valve. When the pressure gets to approximately 300 psi (2050 kPa), it causes load piston relief valve (8) to move to the left against the force of its spring. This causes the remainder of the oil to go to the reservoir and keeps the system pressure below the maximum pressure.
Selector Valve
1. Drain passage.
2. Passage to No. 5 clutch.
3. Inlet passage from the protective valve (P1 pressure).
4. Passage to No. 4 clutch.
5. Drain passage.
6. Passage to No. 7 clutch.
7. Passage to the check valve and orifice of the accumulator group for No. 6 clutch.
8. Selector spools.
9. Passage to the protective valve.
10. Passage to No. 3 clutch.
11. Passage from No. 7 clutch to the shuttle valve.
12. Passage to No. 2 clutch.
13. Inlet passage from the protective valve (P1 pressure).
14. Passage from priority valve (pump pressure).
15. Passage to No. 1 clutch.
SELECTOR VALVE
The selector valve is between the pressure control valve and the accumulator group for No. 6 clutch. The selector valve is made up of four selector spools (8). The spools are connected by linkage to the hydraulic shift spool. The movement of selector spools (8) sends oil to the accumulator group for No. 6 clutch and on to the clutches. The position of the spools determines which clutches are engaged (the speed of the transmission).
Oil from passage (14) is stopped by the spool when the machine is not started in NEUTRAL. This stops the flow of oil through passage (9) to the protective valve.
Accumulator Group For No. 6 Clutch
1. Manifold.
2. Orifice and check valve.
3. Passage from No. 7 clutch.
4. Load piston.
5. Shuttle valve.
6. Passage to lock-up clutch selector valve of the sequence and pressure control valve.
7. Passage from protective valve of the pressure control valve (P1 pressure).
ACCUMULATOR GROUP FOR NO. 6 CLUTCH
The accumulator group for No. 6 clutch is on the bottom of the transmission hydraulic controls. It fastens directly to the transmission and No. 4 clutch housing. This group is made up of shuttle valve (5), load piston (4) for No. 6 clutch, and orifice and check valve (2). This accumulator group is the connection between the selector valve and the transmission.
Shuttle Valve
Shuttle valve (5) is used to give converter drive in reverse. It stops the flow of oil from the pressure control valve to the lock-up clutch selector valve.
Oil, at P1 pressure, comes from the protective valve and goes through passage (7) to shuttle valve (5). The spring and P1 pressure holds the shuttle valve to the left. The oil then goes through passage (6) to the lock-up clutch selector valve to help activate the selector valve which controls the operation of the lock-up clutch.
Passage (3) to shuttle valve (5) comes from No. 7 (reverse) clutch. When the transmission selector lever is in reverse position, oil goes to No. 7 clutch and also to shuttle valve (5). The pressure of the oil in passage (3) causes shuttle valve (5) to move to the right against the force of its spring. This stops the flow of P1 pressure to the lock-up clutch selector valve. The selector valve can not move to operate the lock-up clutch. This action makes sure that the torque converter operates whenever the transmission is in reverse.
Load Piston
Load piston (4) is used to engage No. 6 clutch slowly. Oil comes from orifice and check valve (2) and goes to both load piston (4) and No. 6 clutch. The pressure increases at the load piston at the same time it increases in No. 6 clutch. There is modulation between load piston (4) and No. 6 clutch which causes the pressure to increase gradually. No. 6 clutch engages slowly and makes the shift smoother.
Orifice and Check Valve
ORIFICE AND CHECK VALVE
2. Orifice and check valve. 8. Passage from selector valve. 9. Orifices. 10. Check valve.
Orifice and check valve (2) is used to release No. 6 clutch slowly. Oil comes from the selector valve to passage (8). Check valve (10) permits the oil to flow freely to load piston (4) and No. 6 clutch.
When No. 6 clutch releases, the check valve stops the flow of oil through it and makes the oil go through orifices (9). The pressure of the oil in No. 6 clutch then decreases gradually. No. 6 clutch releases (disengages) slowly and makes the shift smoother.
Operation Of The Automatic Shift Group
When the machine is started in neutral, oil goes from hydraulic oil tank (72), through screen (53), oil pump (44) for the transmission, and oil filter (38) for the transmission to reduction valve (43), manual selector spool (6), downshift reduction valve (3), and priority valve (2).
Reduction valve (3) controls the pressure for the operation of shift spool (50) and lock-up clutch (69) of the torque converter. Lock-up clutch selector valve (52) activates the lock-up clutch.
Manual selector spool (6) is connected by linkage to shift spool (50). Shift spool (50) is activated by oil pressure from either upshift solenoid (47) or downshift solenoid (48). Manual selector spool (6) stops the flow of oil to hold slugs (22) of the automatic selector spools when manual selector spool (6) is in reverse or neutral position. When the manual selector spool is in a forward speed position, it lets oil go to hold slugs (22) through passages 1H through 7H. The transmission hydraulic controls are now in automatic range. The oil in passages 1H through 7H keeps the automatic selector spools from movement.
Oil goes by downshift reduction valve (3) to priority valve (2). The priority valve keeps the pressure in shift pressure valve (1) at approximately 460 psi (3170 kPa) before it permits oil to go to pressure control valve (33) and selector valve (35).
Downshift reduction valve (3) sends oil at about 100 psi (690 kPa) through governor cut-off valve (13) and accumulator group (16) for the governor to governor (11), to hold valve (12), hydraulic shift spool (15), and upshift reduction valves (18, 25 and 26).
During shifts, when P1 pressure in passage (30) decreases, the force of the spring moves spool (8) of governor cut-off valve (13) to stop the flow of oil from governor (11). This action prevents shifts that are not desired and gives a delay in time which lets the clutches go to full pressure between each shift of the transmission.
Accumulator group (16) for the governor is used to keep the pressures constant in governor reduction valves "A" (14) and "B" (19).
Governor (11) has three governor reduction valves (9, 14 and 19). These valves control the upshifts and downshifts of the transmission as the ground speed of the machine increases or decreases. The governor reduction valves send pressures to the inner ends of the automatic selector spools.
Hold valve (18) is used during tests to shift the transmission manually to check the operation of the protective valve, and to check primary pressure. The hold valve stops the flow of oil to hydraulic shift spool (15). Hold valve (18) is activated by air.
When the pressure in the hold slug passage of an automatic selector spool is released (open to drain) the automatic selector spool will move when an upshift or downshift is needed. When the automatic selector spool moves, it causes the pressure in one of passages 1 through 7 to release (go to drain). This pressure decrease causes movement of hydraulic shift spool (15).
Upshift reduction valves (18, 25 and 26) send reference pressures to the outer ends of the automatic selector spools.
Manual Downshifts (Neutral to Reverse)
When the transmission selector level activates downshift solenoid (48) for a shift from neutral to reverse, it lets oil, under pressure from sequence and pressure control valve (46) push shift spool (50) to the left. Movement of shift spool (50) moves manual selector spool (6) to reverse position. The pressure of the oil in passage R goes to drain through the passage in the right end of manual selector spool (6).
Hydraulic shift spool (15) now moves to the right because of the decrease in the pressure in passage R, which causes selector spools (45) to move. The selector spools cause No. 4 clutch to drain and No. 1 and No. 7 clutches to fill and engage. The transmission is now in reverse.
Manual Upshifts (Reverse to Neutral)
When the transmission selector lever activates upshift solenoid (47) for a shift from reverse to neutral, the pressure of the oil from sequence and pressure control valve (46) pushes shift spool (50) to the right. Shift spool (50) moves manual selector spool (6) to neutral position. The pressure of the oil in passage N goes to drain through the passage in the right end of manual selector spool (6).
Hydraulic shift spool (15) now moves to the right because of the decrease in the pressure in passage N. This causes selector spools (45) to move and lets No. 1 and No. 7 clutches drain and No. 4 clutch fill and engage. The transmission is now in neutral.
1. Shift pressure valve.
2. Priority valve.
3. Downshift reduction valve.
4. Line to pressure control valve.
5. Line from transmission oil filter.
6. Manual selector spool.
7. Automatic selector valve.
8. Spool for governor cut-off valve.
9. Governor reduction valve "C".
10. Accumulator for governor reduction valve "B".
11. Shift governor.
12. Hold valve.
13. Governor cut-off valve.
14. Governor reduction valve "A".
15. Hydraulic shift spool.
16. Accumulator group for the governor.
17. Accumulator for governor reduction valve "A".
18. Upshift reduction valve (first to second speed upshift).
19. Governor reduction valve "B".
20. Automatic selector spool (first to second speed shift).
21. Automatic selector spool (sixth to seventh speed shift).
22. Hold slugs (six).
23. Automatic selector spool (second to third speed shift).
24. Automatic selector spool (fifth to sixth speed shift).
25. Upshift reduction valve (second to third, fourth to fifth and sixth to seventh speed upshifts).
26. Upshift reduction valve (third to fourth and fifth to sixth speed upshifts).
27. Automatic selector spool (fourth to fifth speed shift).
28. Automatic selector spool (third to fourth speed shift).
29. Downshift slugs (six).
30. Passage from pressure control valve.
31. Line from governor reduction valve "A".
A. Adjustment screw for all downshift points.
B. Pressure tap for governor supply.
C. Pressure tap for governor reduction valve "C".
D. Pressure tap for governor reduction valve "B".
E. Adjustment screw for priority valve.
F. Adjustment screw for upshift point (first to second speed).
G. Pressure tap for governor reduction valve "A".
H. Adjustment screw for upshift points (second to third, fourth to fifth and sixth to seventh speeds).
J. Adjustment screw for upshift points (third to fourth and fifth to sixth speeds).
AUTOMATIC SHIFT GROUP IN NEUTRAL (ENGINE RUNNING)
4. Line to pressure control valve.
5. Line from transmission oil filter.
30. Passage from pressure control valve.
31. Line from governor reduction valve "A".
32. Passage to transmission lubrication.
33. Pressure control valve.
34. Check valve.
35. Selector valve.
36. Check valve.
37. Flow control valve.
38. Oil filter for transmission.
39. Oil pump for torque converter.
40. Inlet relief valve.
41. Load piston relief valve.
42. Modulation relief valve.
43. Reduction valve.
44. Oil pump for transmission.
45. Selector spools.
46. Sequence and pressure control valve.
47. Upshift solenoid.
48. Downshift solenoid.
49. Load piston.
50. Shift spool.
51. Oil filter for torque converter.
52. Lock-up clutch selector valve.
53. Screen.
54. Oil cooler.
55. Protective valve.
56. Oil pump drive.
57. Torque converter.
58. Load piston for No. 6 clutch.
59. Magnetic screen.
60. Oil filter in hydraulic oil tank.
61. Accumulator group for No. 6 clutch.
62. Shuttle valve.
63. Orifice and check valve.
64. Reservoir in torque converter.
65. Reservoir in transmission.
66. Screen.
67. Brake cooling circuit.
68. Outlet relief valve.
69. Lock-up clutch.
70. Scavenge pump for torque converter.
71. Scavenge pump for transmission.
72. Hydraulic oil tank.
K. Pressure tap for transmission lubrication.
L. P1 pressure tap.
M. Pressure tap for transmission pump.
N. Adjustment screw for lock-up clutch shift points.
P. Pressure tap for torque converter inlet.
R. Pressure tap for torque converter outlet.
PRESSURE AND SELECTOR VALVE GROUP IN NEUTRAL (ENGINE RUNNING)
Manual Upshifts (Neutral to First)
When the transmission selector lever activates upshift solenoid (47) for a shift from neutral to first, the pressure of the oil from sequence and pressure control valve (46) pushes shift spool (50) to the right. Shift spool (50) moves manual selector spool (6) to first speed position.
Pump pressure is now available to all hold passages (passages 1H through 6H). The oil in the hold passages causes each automatic selector spool to move to the inside and each hold slug (22) to move to the outside of automatic selector valve (7).
The pressure of the oil that was in passage 1 now goes to drain because of the movement of automatic selector spool (20). This causes hydraulic shift spool (15) to move to the left until passage 1 is closed by the land on the spool. As hydraulic shift spool (15) moves, selector spools (45) move and No. 4 clutch drains and No. 1 and No. 6 clutches fill and engage. The transmission is now in first speed.
Automatic Upshifts (First to Second)
Upshift reduction valve (18) controls an upshift from first to second speed and gives a reference pressure of about 43 psi (295 kPa). This reference pressure is sent to the outer end of automatic selector spool (20). Governor reduction valve "A" (14) sends a pressure to the inner end of automatic selector spool (20). The pressure from governor reduction valve "A" (14) is controlled by the speed of the output shaft of the transmission (ground speed). The reference pressure from upshift reduction valve (18) works against the pressure from governor reduction valve "A" (14). As the ground speed of the machine becomes faster, governor reduction valve "A" (14) starts to move out and send more pressure oil to the inner end of automatic selector spool (20).
When the transmission selector lever activates upshift solenoid (47) for a shift from first to second speed, the pressure of the oil from sequence and pressure control valve (46) pushes shift spool (50) to the right. Shift spool (50) moves manual selector spool (6) to second speed position. The flow of oil to passage 1H is stopped and the pressure at passage. 1H at automatic selector spool (20) decreases. At this time, automatic selector spool (20) is not held in position by the oil pressure in the hold slug.
When the pressure from governor reduction valve "A" (14) is higher (as ground speed increases) than the reference pressure from upshift reduction valve (18), the pressure from governor reduction valve "A" (14) will cause automatic selector spool (20) and its hold slug to move completely to the right. This causes the oil in passage 2 to drain. The pressure of the oil, on the left side of the land on hydraulic shift spool (15), decreases and drains through passage 2. This causes the pressure of the oil, on the right side of the land on hydraulic shift spool (15), to move the hydraulic shift spool to the left.
Selector spools (45) are moved by hydraulic shift spool (15) and No. 3 and No. 6 clutches fill and engage. The transmission is now in second speed.
Automatic Upshifts (Second to Third)
Upshift reduction valve (25) controls an upshift from second to third, fourth to fifth, and sixth to seventh speeds. It gives a reference pressure of approximately 83 psi (570 kPa). This reference pressure is sent to the outer ends of automatic selector spools (21, 23 and 27). Governor reduction valve "A" (14) sends a pressure to the inner end of automatic selector spool (23). The pressure from governor reduction valve "A" (14) is controlled by the speed of the output shaft of the transmission (ground speed). The reference pressure from upshift reduction valve (25) works against the pressure from governor reduction valve "A"(14). As the ground speed of the machine becomes faster, governor reduction valve "A" (14) starts to move out and send more pressure oil to the inner end of automatic selector spool (23).
When the transmission selector lever activates upshift solenoid (47) for a shift from second to third speed, the pressure of the oil from sequence and pressure control valve (46) pushes shift spool (50) to the right. Shift spool (50) moves manual selector spool (6) to third speed position. The flow of oil to passage 2H is stopped and the pressure at passage 2H at automatic selector spool (23) decreases. At this time, automatic selector spool (23) is not held in position by the oil pressure in the hold slug.
When the pressure from governor reduction valve "A" (14) is higher (as ground speed increases) than the reference pressure from upshift reduction valve (25), the pressure from governor reduction valve "A" (14) will cause automatic selector spool (23) and its hold slug to move completely to the right. This causes the oil in passage 3 to drain. The pressure of the oil, on the left side of the land on hydraulic shift spool (15), decreases and drains through passage 3. This causes the pressure of the oil, on the right side of the land on hydraulic shift spool (15), to move the hydraulic shift spool to the left.
Selector spools (45) are moved by hydraulic shift spool (15) and No. 2 and No. 6 clutches fill and engage. The transmission is now in third speed.
Automatic Upshifts (Third to Fourth)
Upshift reduction valve (26) controls an upshift from third to fourth and fifth to sixth speeds. It gives a reference pressure of approximately 46 psi (320 kPa). This reference pressure is sent to hold slugs at the outer ends of automatic selector spools (24 and 28). Governor reduction valve "B" (19) sends a pressure to the inner end of automatic selector spool (28). The pressure from governor reduction valve "B" (19) is controlled by the speed of the output shaft of the transmission (ground speed). The reference pressure from upshift reduction valve (26) works against the pressure from governor reduction valve "B" (19). As the ground speed of the machine becomes faster, governor reduction valve "B" (19) starts to move out and send more pressure oil to the inner end of automatic selector spool (28).
When the transmission selector lever activates upshift solenoid (47) for a shift from third to fourth speed, the pressure of the oil from sequence and pressure control valve (46) pushes shift spool (50) to the right. Shift spool (50) moves manual selector spool (6) to fourth speed position. The flow of oil to passage 3H is stopped and the pressure at passage 3H at automatic selector spool (28) decreases. At this time, automatic selector spool (28) is not held in position by the oil pressure in the hold slug.
When the pressure from governor reduction valve "B" (19) is higher (as ground speed increases) than the reference pressure from upshift reduction valve (26), the pressure from governor reduction valve "B" (19) will cause automatic selector spool (28) and its hold slug to move completely to the right. This causes the oil in passage 4 to drain. The pressure of the oil, on the left side of the land on hydraulic shift spool (15), decreases and drains through passage 4. This causes the pressure of the oil, on the right side of the land on hydraulic shoft spool (15) to move the hydraulic shift spool to the left.
Selector spools (45) are moved by hydraulic shift spool (15) and No. 3 and No. 5 clutches fill and engage. The transmission is now in fourth speed.
Automatic Upshifts (Fourth through Seventh)
The sequence of each automatic upshift is the same except different upshift reduction valves, automatic selector spools, governor reduction valves, and passages are used.
With the transmission selector lever in seventh speed, there is an upshift from fourth to fifth speeds when the pressure from governor reduction valve "B" (19) moves automatic selector spool (27) to the left. This opens passage 5 to drain and keeps oil from passage 4 in the drain passage at the left end of automatic selector spool (28). As the ground speed of the machine increases, pressure from governor reduction valve "C" (9) causes automatic selector spool (24) to move to the right and there is an upshift from fifth to sixth speeds.
As the ground speed increases, automatic selector spool (21) moves to the left which causes an upshift from sixth to seventh speeds.
Automatic Downshifts
Downshift reduction valve (3) causes all six downshifts. Each downshift is made as the ground speed of the machine becomes slower. When the pressure from the governor reduction valve plus the pressure at the inner end of an automatic selector spool becomes lower than the reference pressure on the outer end of an automatic selector spool, the automatic selector spool moves toward the inside.
The movement of the automatic selector spool opens and drains a passage from hydraulic shift spool (15). The hydraulic shift spool then moves to close this passage and the transmission makes a shift to the next lower speed.
In a third to second speed downshift, when the ground speed of the machine decreases, the pressure from governor reduction valve "A" (14) at the inner end of automatic selector spool (23) becomes lower than the reference pressure from pressure reduction valve (25) on the outer end of automatic selector spool (23). Automatic selector spool (23) moves to the left. This closes passage 3 and opens passage 2 to drain at automatic selector spool (23). Passage 2 at hydraulic shift spool (15) is also open. Oil in passage 2 goes out the passage in automatic selector valve (7) at the left end of hydraulic shift spool (15). This causes a pressure differential between both ends of hydraulic shift spool (15). The pressure at the left moves the hydraulic shift spool to the right. The hydraulic shift spool moves to the right until its land is over passage 2. When the hydraulic shift spool moves, it moves selector spools (45) in selector valve (35). Now, the transmission makes the shift to second speed. After the shift is made, passage 2 is closed by the land of hydraulic shift spool (15). The pressure at the right end of the hydraulic shift spool becomes the same as the pressure on the left end. Since there is no pressure differential, hydraulic shift spool (15) does not move any farther. It is held in second speed. The sequence of each automatic downshift is the same, except different automatic selector spools, governor reduction valves, and passages are used.
1. Shift pressure valve.
2. Priority valve.
3. Downshift reduction valve.
4. Line to pressure control valve.
5. Line from transmission oil filter.
6. Manual selector spool.
7. Automatic selector valve.
8. Spool for governor cut-off valve.
9. Governor reduction valve "C".
10. Accumulator for governor reduction valve "B".
11. Shift governor.
12. Hold valve.
13. Governor cut-off valve.
14. Governor reduction valve "A".
15. Hydraulic shift spool.
16. Accumulator group for the governor.
17. Accumulator for governor reduction valve "A".
18. Upshift reduction valve (first to second speed upshift).
19. Governor reduction valve "B".
20. Automatic selector spool (first to second speed shift).
21. Automatic selector spool (sixth to seventh speed shift).
22. Hold slugs (six).
23. Automatic selector spool (second to third speed shift).
24. Automatic selector spool (fifth to sixth speed shift).
25. Upshift reduction valve (second to third, fourth to fifth and sixth to seventh speed upshifts).
26. Upshift reduction valve (third to fourth and fifth to sixth speed upshifts).
27. Automatic selector spool (fourth to fifth speed shift).
28. Automatic selector spool (third to fourth speed shift).
29. Downshift slugs (six).
30. Passage from pressure control valve.
31. Line from governor reduction valve "A".
A. Adjustment screw for all downshift points.
B. Pressure tap for governor supply.
C. Pressure tap for governor reduction valve "C".
D. Pressure tap for governor reduction valve "B".
E. Adjustment screw for priority valve.
F. Adjustment screw for upshift point (first to second speed).
G. Pressure tap for governor reduction valve "A".
H. Adjustment screw for upshift points (second to third, fourth to fifth and sixth to seventh speeds).
j. Adjustment screw for upshift points (third to fourth and fifth to sixth speeds).
AUTOMATIC SHIFT GROUP IN FIRST SPEED (CONVERTER DRIVE)
4. Line to pressure control valve.
5. Line from transmission oil filter.
30. Passage from pressure control valve.
31. Line from governor reduction valve "A".
32. Passage to transmission lubrication.
33. Pressure control valve.
34. Check valve.
35. Selector valve.
36. Check valve.
37. Flow control valve.
38. Oil filter for transmission.
39. Oil pump for torque converter.
40. Inlet relief valve.
42. Modulation relief valve.
43. Reduction valve.
44. Oil pump for transmission.
45. Selector spools.
46. Sequences and pressure control valve.
47. Upshift solenoid.
48. Downshift solenoid.
49. Load piston.
50. Shift spool.
51. Oil filter for torque converter.
52. Lock-up clutch selector valve.
53. Screen.
54. Oil coller.
55. Protective valve.
56. Oil pump drive.
57. Oil pump drive.
58. Load piston for No. 6 clutch.
59. Oil filter in hydraulic oil tank.
61. Accumulator group for No. 6 clutch.
62. Shuttle valve.
63. Orifice and check valve.
64. Reservoir in torque converter.
65. Reservoir in tranmission.
66. Screen.
67. Brake cooling circuit.
68. Outlet relief valve.
69. Lock-up clutch.
70. Scavenge pump for torque converter.
71. Scavenge pump for transmission.
72. Hydraulic oil tank.
K. Pressure tap for transmission lubrication.
L. P1 pressure tap.
M. Pressure tap for transmission pump.
N. Adjustment screw for lock-up clutch shift points.
P. Pressure tap for torque converter inlet.
R. Pressure tap for torque converter outlet.
PRESSURE AND SELECTOR VALVE GROUP IN FIRST SPEED (CONVERTER DRIVE)
If the transmission is in a speed and the control lever is moved to a lower speed, the transmission will not make a shift unless the ground speed of the machine is slow enough. Pressure from a governor reduction valve must decrease before the automatic selector spool will move. Hold slugs (22) do not get pressure until the reference pressure on the outer end of the automatic selector spool moves the spool to the inside. After the automatic selector spool starts to move, it opens the chamber of the hold slug to pump pressure from manual selector spool (6). The automatic selector spool then moves quickly (faster) to the right and makes a downshift.
The only time the transmission will make a downshift when the ground speed of the machine is slow enough to permit the downshift.
Operation Of The Pressure And Selector Valve Group
Neutral
When the machine is started in neutral, oil comes from priority valve (2) to pressure control valve (33) and selector valve (35). This oil divides and goes to the right end of flow control valve (37); through an orifice in pressure control valve (33), into the spring passage of flow control valve (37), and also to modulation relief valve (42); and to one of selector spools (45).
Flow control valve (37) makes sure there is 15 U.S. gpm (57 litre/min) of oil available to fill the clutches. The remainder of the oil from flow control valve (37) and modulation relief valve (42) goes to the transmission lubrication system.
When the machine is not started in neutral, protective valve (55) stops the flow of oil from modulation relief valve (42) to the clutches. One of selector spools (45) stops the flow of oil to protective valve (55) so that the valve will not move to the right and let oil go to the clutches.
When the machine is started in neutral, oil goes from the selector spool to the orifice in protective valve (55). The pressure of the oil increases and pushes the protective valve to the right which permits oil to flow from modulation relief valve (42) to the clutches and the remainder of pressure control valve (33).
As protective valve (55) moves to the right, the oil goes two different ways. The oil goes through a passage to check valve (34). It then goes through an orifice to load valve (36) where the oil is stopped. The pressure of the oil and the force of the spring cause check valve (34) to move to the right and stop the flow of oil from the load piston to the reservoir. The orifice causes a short delay in the increase of the pressure to load piston (49) and load piston relief valve (41). The pressure starts to increase behind load piston (49).
At the same time the oil goes to check valve (34), it also goes to selector spools (45) in selector valve (35). The position of the spools permits the oil to fill No. 4 clutch for neutral. The pressure now goes up immediately to the primary setting of modulation relief valve (42) (the valve moves to the right and releases pressure to the transmission lubrication system).
The pressure now increases at load piston (49) and causes it to move to the left. The spring between load piston (49) and modulation relief valve (42) causes the modulation relief valve to also move to the left. The pressure again increases which causes modulation relief valve (42) to move to the right. The increase in pressure again causes load piston (49) to move to the left. This again causes modulation relief valve (42) to move to the left and the pressure again increases.
This cycle, of the gradual increase in pressure (modulation), is caused by the orifice between modulation relief valve (42), and load piston (49). The cycle takes place again and again until the pressure of the oil on load piston relief valve (41) becomes greater than the force of its spring. This causes the relief valve to move to the left against the force of the spring and the extra oil will go to drain. The pressure at P1 is now approximately 300 psi (30540 kPa).
In neutral position, load piston (49) does not move all the way to the left. The clutches are not at maximum pressure (converter drive pressure). The clutches are at direct drive pressure.
Direct Drive (Second through Seventh)
The normal pressures in direct drive are lower than the pressures for converter drive because No. 1 clutch is not engaged. When No. 1 clutch is not engaged, there is no pressure in the spring chamber at the left of load piston relief valve (41). The valve is now free to operate. When the pressure in the chamber at load piston (49) gets to approximately 300 psi (2050 kPa), the relief valve will move to the left and let the extra oil go to the reservoir. This keeps the pressure much lower than maximum (converter drive) pressure of about 410 psi (2820 kPa).
All upshifts and downshift are made from a direct drive speed to a direct drive speed. The only difference is in a first to second upshift or a second to first downshift.
In a first to second speed upshift, the pressure in the clutches is at its maximum (converter drive pressure). When the shift is made, the pressure decreases to fill pressure and then only increases to the setting of load piston relief valve (41) (direct drive pressure).
In a second to first speed downshift, the pressure is at the setting of load piston relief valve (41) (direct drive pressure). When the shift is made, the pressure decreases to fill pressure and then increases to its maximum (converter drive pressure).
When a shift is made from one direct drive speed to another, P1 pressure decreases to fill pressure. The clutches start to fill for the next desired speed. This lower pressure lets check valve (34) move to the left. This lets the oil behind load piston (49) go to drain and load piston (49) moves all the way to the right.
At this same time, the pressure from governor reduction valve "A" (14) decreases. With P1 pressure and governor pressure decreased, the load piston for lock-up clutch selector valve (52) moves to the left. This lets the selector valve move to the left and stops and flow of oil to lock-up clutch (69). The machine is now back in converter drive. This action takes place between each direct drive speed to make shifts smoother.
When the clutches are filled, modulation takes place until direct drive pressure (or converter drive pressure during a downshift from second to first) is reached. The pressure on the load piston of lock-up clutch selector valve (52) increases again. When the pressure from governor reduction valve "A" (14) gets high enough, the selector valve moves to the right and lock-up clutch (69) engages again.
The operation of flow control valve (37) is the same in direct drive as in converter drive, except at a lower pressure. Load piston (58) and orifice and check valve (63) of accumulator group (61), for No. 6 clutch operate the same in second and third speeds as in first speed.
Converter Drive (First and Reverse)
First Speed (Converter and Direct Drive)
When a shift is made to first speed, the movement of oil through pressure control valve (33) is similar to the flow of the oil in neutral. Protective valve (55) opens and lets oil go to load piston (49) and modulation takes place.
Selector spools (45) start to fill No. 1 and No. 6 clutches because of the position of the spools. The passage to No. 1 clutch is connected to a passage that goes to the spring chamber of load piston relief valve (41). The pressure of the oil in No. 1 clutch and the spring hold the relief valve to the right and will not let it operate. The oil then goes through another orifice and check valve (36) to load piston (49). This causes the load piston to move all the way to the left and modulation relief valve (42) will go to its maximum setting (converter drive pressure).
The oil that goes to No. 6 clutch, first goes through orifice and check valve (63). As No. 6 clutch fills, the oil also goes to load piston (58) of accumulator group (61) for No. 6 clutch. Load piston (58) causes No. 6 clutch to engage gradually which makes a smoother shift (engagement). When No. 6 clutch is released (disengages), the orifice of orifice and check valve (63) causes a slow release (disengagement) of No. 6 clutch.
Oil from protective valve (55) also goes to shuttle valve (62) and on to the load piston of lock-up clutch selector valve (52). In first speed when the pressure of the oil from governor reductive valve "A" (14) gets high enough (ground speed increases), this pressure and P1 pressure will cause lock-up clutch selector valve (52) to move to the right. This lets oil go from reduction valve (43) to lock-up clutch (69). The machine now goes from converter drive to direct drive.
1. Shift pressure valve.
2. Priority valve.
3. Downshift reduction valve.
4. Line to pressure control valve.
5. Line from transmission oil filter.
6. Manual selector spool.
7. Automatic selector valve.
8. Spool for governor cut-off valve.
9. Governor reduction valve "C".
10. Accumulator for governor reduction valve "B".
11. Shift governor.
12. Hold valve.
13. Governor cut-off valve.
14. Governor reduction valve "A".
15. Hydraulic shift spool.
16. Accumulator group for the governor.
17. Accumulator for governor reduction valve "A".
18. Upshift reduction valve (first to second speed upshift).
19. Governor reduction valve "B".
20. Automatic selector spool (first to second speed shift).
21. Automatic selector spool (sixth to seventh speed shift).
22. Hold slugs (six).
23. Automatic selector spool (second to third speed shift).
24. Automatic selector spool (fifth to sixth speed shift).
25. Upshift reduction valve (second to third, fourth to fifth and sixth to seventh speed upshift).
26. Upshift reduction valve (third to fourth and fifth to sixth speed upshift).
27. Automatic selector spool (fourth to fifth speed shifts).
28. Automatic selector spool (third to fourth speed shifts).
29. Downshift slugs (six).
30. Passage from pressure control valve.
31. Line from governor reduction valve "A".
A. Adjustment screw for all downshift points.
B. Pressure tap for governor supply.
C. Pressure tap for governor reduction valve "C".
D. Pressure tap for governor reduction valve "B".
E. Adjustment screw for priority valve.
F. Adjustment screw for upshift point (first to second speed).
G. Pressure tap for governor reduction valve "A".
H. Adjustment screw for upshift points (second to third, fourth to fifth and sixth to seventh speeds).
J. Adjustment screw for upshift points (third to fourth and fifth to sixth speeds).
AUTOMATIC SHIFT GROUP IN SEVENTH SPEED
4. Line to pressure control valve.
5. Line from transmission oil filter.
30. Passage from pressure control valve.
31. Line from governor reduction valve "A".
32. Passage to transmission lubrication.
33. Pressure control valve.
34. Check valve.
35. Selector valve.
36. Check valve.
37. Flow control valve.
38. Oil filter for transmission.
39. Oil pump for torque converter.
40. Inlet relief valve.
41. Load piston relief valve.
42. Modulation relief valve.
43. Reduction valve.
44. Oil pump for transmission.
45. Selector spools.
46. Sequence and pressure control valve.
47. Upshift solenoid.
48. Downshift solenoid.
49. Load piston.
50. Shift spool.
51. Oil filter for torque converter.
52. Lock-up clutch selector valve.
53. Screen.
54. Oil cooler.
55. Protective valve.
56. Oil pump drive.
57. Torque converter.
58. Load piston for No. 6 clutch.
59. Magnetic screen.
60. Oil filter in hydraulic oil tank.
61. Accumulator group for No. 6 clutch.
62. Shuttle valve.
63. Orifice and check valve.
64. Reservoir in torque converter.
65. Reservoir in transmission.
66. Screen.
67. Brake cooling circuit.
68. Outlet relief valve.
69. Lock-up clutch.
70. Scavenge pump for torque converter.
71. Scavenge pump for transmission.
72. Hydraulic oil tank.
K. Pressure tap for transmission lubrication.
L. P1 pressure tap.
M. Pressure tap for transmission pump.
N. Adjustment screw for lock-up clutch shift points.
P. Pressure tap for torque converter inlet.
R. Pressure tap for torque converter outlet.
PRESSURE AND SELECTOR VALVE GROUP IN SEVENTH SPEED
Reverse (Converter Drive Only)
When a shift is made to reverse, selector spools (45) start to fill No. 1 and No. 7 clutches. Whenever a shift is made, the pressure at P1 decreases to fill pressure. The oil behind load piston (49) pushes check valve (34) to the left and goes to drain. After the clutches fill, the pressure immediately goes to the primary setting.
The oil that goes to No. 1 clutch again holds load piston relief valve (41) to the right, modulation takes place, and modulation relief valve (42) goes to its maximum setting (converter drive pressure).
The oil that goes to No. 7 clutch also goes to the left end of shuttle valve (62). This pushes shuttle valve (62) to the right against the force of its spring and stops the flow of oil from protective valve (55) to lock-up clutch selector valve (52). This action keeps the machine in converter drive at all times in reverse.
Standard Differential
1. Yoke.
2. Bevel pinion.
3. Housing.
4. Side gears (two).
5. Thrust pin.
6. Bearings (two).
7. Bevel gear.
8. Housing.
9. Spider.
10. Thrust washers (four).
11. Spider pinions (four).
12. Carrier assembly.
13. Thrust washers (two).
DIFFERENTIAL AND BEVEL GEAR
The differential and bevel gear is fastened to the rear axle housing. It connects the rear drive shaft to the drive axles. The rear drive shaft is fastened to yoke (1). Yoke (1) turns bevel pinion (2), which turns bevel gear (7). Bevel gear (7) is fastened to the differential housing. There are four spider pinions (11) which turn freely on spider (9). Housing (3) and housing (8) are bolted together to make the differential housing. The housing is driven by bevel gear (7) and held by bearings (6). Correct adjustment of these bearings is very important.
Spider pinions (11) are engaged at a 90° angle with two side gears (4). The side gears are connected to the drive axles by splines. Side gears (4) turn against thrust washers (13). End thrust of spider pinions (11), against the differential housing, is taken by thrust washers (10). The thrust washers must be changed in sets.
When the machine moves straight forward, both wheels get the same amount of load, if the traction under both wheels is the same. The same amount of torque on each axle will stop spider pinions (11) from rotation on spider (9). This will give the same effect as if both drive wheels are fastened to the same drive axle.
When different loads are put on the drive wheels, as in a turn or with one wheel in free rotation, spider pinions (11) will turn because the forces are not the same on the opposite sides of the differential. The rotation of spider pinions (11) will permit the inside wheel to go slower and the outside wheel to go faster.
The differential gets lubrication from the oil in the rear axle housing. As the parts turn, the oil is thrown around inside of the housing (splash lubricated). Spiral grooves in thrust washers (13) let the lubricant flow between thrust washers and side gears (4).
Thrust pin (5) stops carrier assembly (12) from movement from side to side while the machine is in operation.
Nospin Differential Group
NOSPIN DIFFERENTIAL GROUP
1. Bevel gear. 2. Yoke. 3. NOSPIN differential. 4. Bevel pinion.
The NOSPIN differential group has a bevel gear (1), a yoke (2), a NOSPIN differential (3) and a bevel pinion (4).
The flow of power from the transmission through the differential is:
... From the transmission through the rear drive shaft to yoke (2).
... From yoke (2) to bevel pinion (4).
... From bevel pinion (4) to bevel gear (1).
... From bevel gear (1) to the differential housing.
... From the differential housing through the four trunnions to NOSPIN differential (3).
... From NOSPIN differential (3) to the drive axles.
When the speeds of the wheels are the same, the NOSPIN differential sends the same amount of torque to each wheel. When the speeds of the wheels are different, the NOSPIN differential sends the torque to the wheel that turns slower. A difference in the speeds of the wheels is caused by a turn.
The NOSPIN differential lets a wheel (axle) turn faster than the speed of the bevel gear by not engaging it with the bevel gear. For example: During a turn with power, the outside wheel (axle) is not engaged with the bevel gear and turns faster while the inside wheel (axle) is engaged with the bevel gear and turns at the same speed as the bevel gear. The inside wheel gives the power which moves the machine through the turn.
The NOSPIN differential is the same on one side of spider (17) as it is on the other side (symmetrical). The NOSPIN has two springs (7) and (10), two side gears (5) and (12), two driven clutches (6) and (11), two holdout rings (8) and (9), a center cam (15), a snap ring (16) and a spider (17).
The inside splines of side gears (5) and (12) are connected to the drive axles. The outside splines of the side gears are connected to the inside splines of drive clutches (6) and (11). The side gears send the power through the axles to the wheels.
NOSPIN DIFFERENTIAL (Assembled)
5. Side gear. 6. Driven clutch. 7. Spring. 8. Holdout ring. 9. Holdout ring. 10. Spring. 11. Driven clutch. 12. Side gear. 13. Spring retainer. 14. Spring retainer. 15. Center cam. 16. Snap ring. 17. Spider.
Spider (17) is fastened to the differential case and turns at the speed of the bevel gear. The spider has clutch teeth on both sides. The spider also has one long tooth. The long tooth is spider key (19). Center cam (15) fits inside the spider and is held in position by snap ring (16). The center cam is turned by spider key (19) which fits inside notch (18). The spider key pushes on either side of notch (18). The direction of the machine, forward or reverse, controls which way the spider turns and which side of notch (18) gets the force.
NOSPIN DIFFERENTIAL (Left Side Disassembled)
5. Side gear. 6. Driven clutch. 7. Spring. 8. Holdout ring. 13. Spring retainer. 15. Center cam. 16. Snap ring. 17. Spider.
Springs (7) and (10) fit between the side gears and spring retainers (13) and (14). The outside splines of the spring retainers are connected to the inside splines of the driven clutches. The force of the springs holds the driven clutches against spider (17) and the side gears against the differential case.
SPIDER AND CENTER CAM
15. Center cam. 17. Spider. 18. Notch in center cam. 19. Spider key.
Driven clutches (6) and (11) are the same. Each driven clutch has a cam (21) which is part of the clutch. The teeth on the cam engage with the teeth of center cam (15). The teeth of the drive clutches engage with the teeth of spider (17). An annular (in the shape of a circle) groove is between the teeth of the driven clutches and the teeth of the cams.
CLUTCH AND HOLDOUT RING
6. Driven clutch. 8. Holdout ring. 20. Notch in holdout ring. 21. Cam.
Holdout rings (8) and (9) are the same. Each holdout ring fits in the annular groove between the teeth of the driven clutches and the teeth of the cams. The teeth of the holdout rings engage with the notches in the center cam. Notch (20) in the holdout ring engages with spider key (19). The spider key controls the movement of the holdout ring in relation to the spider. There is no connection, except friction, between the holdout rings and the drive clutches.
Operation Of Nospin Differential
When a wheel is made to turn faster than the speed of the bevel gear, the "clutch action" (the stopping of power to a drive axle) of the NOSPIN differential will let this axle turn faster than the speed of the bevel gear.
The "clutch action" of the NOSPIN differential is as follows: If spider (17) turns, spider key (19) locates center cam (15) and the spider and the center cam turn at the speed of the bevel gear. The center cam turns holdout ring (8) and cam (21) at the speed of the bevel gear. The spider turns driven clutch (6) at the speed of the bevel gear. The driven clutch turns the side gear, axle, and wheel at the speed of the bevel gear.
When the wheel is made to turn faster than the speed of the bevel gear, the teeth of center cam (15) work like ramps and the teeth of cam (21) move up the teeth of the center cam. This action causes driven clutch (6) to become not engaged with the spider. The driven clutch pulls holdout ring (8) out of the grooves in the center cam. The friction between the holdout ring and driven clutch turns the holdout ring until notch (20) in the holdout ring engages with spider key (19). The holdout ring is now turned by the spider key at the speed of the bevel gear. The teeth of the holdout ring are now in a position so they can not engage the notches in the center cam. The driven clutch and cam move around the holdout ring at a speed faster than the speed of the bevel gear. The holdout ring keeps the driven clutch and cam from being engaged (engagement) with the center cam and spider. The driven clutch, cam, axle shaft and wheel now turn freely.
The opposite side clutch, cam, and holdout ring are held engaged to the center cam and spider by spring (7) as long as the driven wheel turns slower.
When the speed of the wheel that is not engaged becomes slower and near the speed of the bevel gear, the resistance of the ground to the wheel causes the torque on this wheel to be in a small reverse direction. This causes the driven clutch and cam to turn in a direction opposite the direction of the bevel gear. The friction between the holdout ring and the driven clutch causes the holdout ring to move in a direction opposite the direction of the bevel gear. Notch (20) in the holdout ring moves away from spider key (19). When the teeth of the holdout ring are in a position to engage the notches in center cam (15), the force of the spring causes the driven clutch and cam to move to the inside. The driven clutch pushes the holdout ring. The holdout ring now engages the center cam and is turned at the speed of the bevel gear. The teeth of cam (21) now engage the center cam and the teeth of the drive clutch engage the spider. At this time, both wheels are turned at the same speed.
NOTE: When both wheels are turned at the same speed they do not necessarily have equal torque. For example: When one wheel starts to turn faster on ice (tends to spin out), both clutches engage and both wheels turn at the same speed. The wheel that is on ice will have less torque.
Straight Forward Operation
When the machine has straight forward movement, teeth (22) on both sides of spider (17) are fully engaged with teeth (23) of the driven clutches (6) and (11). The teeth of cams (21) are engaged with the teeth of center cam (15). The negative angle of the teeth on the clutches and spider, along with the force of springs (7) and (11), cams (21) and center cam (15), push together and the teeth engage.
STRAIGHT FORWARD OPERATION
5. Side gear. 6. Driven clutch. 11. Driven clutch. 12. Side gear. 17. Spider. 22. Teeth of the spider. 23. Teeth of the driven clutches.
In this condition, driven clutches (6) and (11) are fully engaged with spider (17). The driven clutches turn side gears (5) and (12) at the same speed as the bevel gear. The two side gears turn the axle shafts and wheels at the same speed as the bevel gear.
Forward Turn With Power
The travel of the outside wheel, during a turn, is at a longer distance than the travel of the inside wheel. When the machine turns with power, the NOSPIN differential lets the outside wheel turn faster than the speed of the bevel gear (to let the outside wheel have this longer travel) but does not let the inside wheel turn slower than the speed of the bevel gear. The inside wheel turns at the same speed as the bevel gear.
The teeth of the spider send the drive force to the inside driven clutch. The inside driven clutch turns the inside wheel at the same speed as the bevel gear and gives the power that is needed to move the m':chine through the turn.
The outside wheel is made to turn (by the traction of the road) at a speed faster than the speed of the bevel gear. This causes the driven clutch for the outside wheel to turn faster than the speed of the bevel gear. The movement of one wheel faster than the other wheel starts the "clutch action" of the NOSPIN differential.
FORWARD RIGHT TURN WITH POWER
5. Side gear. 6. Driven clutch. 11. Driven clutch. 12. Side gear. 17. Spider.
The teeth of the cam for the driven clutch for the inside wheel are engaged with the teeth of center cam (15) and stay in the same position in relation to spider (17). The teeth of the inside drive clutch are engaged with the spider. The teeth on the other side of center cam (15) are used as ramps. The teeth of the cam for the driven clutch for the outside wheel move up the teeth of the center cam. This causes the outside driven clutch and cam to move away from the spider and center cam. The outside driven clutch and cam are not engaged with the spider and center cam.
The driven clutch for the outside wheel can not be engaged with the spider until the speed of the outside wheel becomes slower and equal to the speed of the bevel gear. The holdout ring keeps the driven clutch and cam from being engaged with the spider and center cam until the machine moves in a straight direction. At this time the operation of the differential is the same as STRAIGHT FORWARD OPERATION.
Straight Reverse Operation
When the machine moves in a straight reverse direction, teeth (22) on both sides of spider (17) are fully engaged with teeth (23) of driven clutches (6) and (11). The spider (17) turns in the opposite direction than it turns in straight forward. Since the spider turns in an opposite direction, teeth (22) of the spider push against the opposite face of teeth (23) of the driven clutches.
STRAIGHT REVERSE
5. Side gear. 6. Driven clutch. 11. Driven clutch. 12. Side gear. 17. Spider. 22. Teeth of the spider. 23. Teeth of the driven clutches.
The action of the differential is the same as it is in the STRAIGHT FORWARD DIRECTION.
Reverse Turn With Power
The action of the differential is the same as it is in the FORWARD TURN WITH POWER condition except spider (17) turns in the opposite direction.
REVERSE RIGHT TURN WITH POWER
5. Side gear. 6. Driven clutch. 11. Driven clutch. 12. Side gear. 17. Spider.
Forward Turn With No Power
The operation of the NOSPIN differential is the same as for FORWARD TURN WITH POWER. The outside wheel is still made to turn faster (by the traction of the road) than the speed of the bevel gear. The inside wheel is turned at the speed of the bevel gear.
Reverse Turn With No Power
The operation of the NOSPIN differential is the same as for REVERSE TURN WITH POWER. The outside wheel is still made to turn faster (by the traction of the road) than the speed of the bevel gear. The inside wheel is turned at the speed of the bevel gear.
Final Drive
PLANETARY DRIVE
1. Axle shaft. 2. Final drive hub. 3. Ring gear. 4. Planetary gears. 5. Sun gear. 6. Planetary carrier.
The final drive is a planetary gear-type system. Ring gear (3) is connected to final drive hub (2). Final drive hub (2) is fastened to the axle housing. Ring gear (3) is stationary. Planet gears (4) are held by planetary carrier (6), which is connected to the wheel assembly. Sun gear (5) is connected to the wheel assembly. Sun gear (5) is connected with splines to axle shaft (1), which is driven by the inside of ring gear (3) in the same direction, but at a slower speed. Planetary carrier (6) will turn the wheel assembly.
The final drives get lubrication by the rotation of the gears in oil (splash lubrication). The differential and final drives use the same lubricant.