General Information - (Power Shift)

Location Of Components 1. Transmission hydraulic controls. 2. Flexible coupling drive. 3. Diesel engine. 4. Steering clutches. 5. Final drive. 6. Range transmission. 7. Torque converter.

Power from the diesel engine (3) is sent through the engine flywheel and flexible coupling drive (2) to torque converter (7). The torque converter drives sun gears and planet gears in the transmission.

Five planetary gear trains, each with its own clutch, give the tractor three speeds in either FORWARD or REVERSE. The selection of the desired tractor speed is done manually by the operator but hydraulic oil, directed by transmission hydraulic controls (1), engages the clutches in the transmission.

A bevel pinion in the transmission group, sends power from transmission (6) to the bevel gear. The power is sent through steering clutches (4) into final drives (5), to the sprockets which drive the tracks.

The steering clutch and bevel gear case houses the bevel gear, steering clutches and brakes.

The steering clutches are used to turn the tractor. The brakes are used to stop the tractor and give assistance to the action of the steering clutches.

Location Of Components 1. Transmission. 2. Universal joint. 3. Diesel engine. 4. Steering clutch. 5. Final Drive. 6. Lower countershaft in transmission. 7. Flywheel clutch.

Power from diesel engine (3) is sent from the engine to flywheel clutch (7). The flywheel clutch is engaged and disengaged manually. The output shaft of the flywheel clutch drives the upper shaft in transmission (1) through a universal joint (2).

The transmission has five FORWARD and five REVERSE speeds. The selection of these speeds is done manually. The bevel pinion, at the rear of the transmission, sends the power to the bevel gear. The power is then sent through steering clutches (4) into final drives (5), to the sprockets which drive the tracks.

The steering clutch and bevel gear case houses the bevel gear, steering clutches and brakes.

The steering clutches are used to turn the tractor. The brakes are used to stop the tractor and give assistance to the action of the steering clutches.

Hydraulic System - (Power Shift)

Location Of Components 1. Transmission hydraulic controls. 2. Oil filter. 3. Oil pump. 4. Oil cooler. 5. Transmission sump. 6. Screen. 7. Torque converter.

A gear-type oil pump is used to supply oil to control the transmission, charge the torque converter, disengage the steering clutches and send lubrication to the transmission and converter.

Oil pump (3) is fastened to the top right side of the torque converter housing. The pump is in operation whenever the engine is run. Oil from sump (5) enters pump (3) and is sent to oil filter (2). If there is a restriction in the filter element, a bypass valve in the filter housing will open. From the filter the pressure oil enters the priority valve. From the priority valve the oil is directed to the transmission controls and to the steering control valve.

Valves in the hydraulic controls control oil flow to the transmission clutches and torque converter. Oil not needed to fill the clutches is sent into the converter. From the converter, the oil flows through an oil cooler to the lubrication relief valve. The relief valve limits the pressure of the lubricant in the planetary transmission.

Transmission Lubrication

Passages in the No. 1, No. 2 and No. 3 clutch housings direct lube oil to spray on the No. 1 and No. 2 clutches and, provide pressure oil for lubrication of the planet gears and bearings in the No. 1, No. 2, No. 3 and No. 4 carriers. A passage in the rear manifold directs lube oil to the No. 5 clutch components. All lubricating oil in the transmission, including that bypassed by the lubrication relief valve, returns to the sump.

Hydraulic Pump

Components Of Hydraulic Pump 1. Base assembly. 2. Body assembly. 3. Cover assembly. 4. Drive gear. 5. Idler gear. 6. Seals. 7. Bearings.

The location of the hydraulic pump is on the front side of the torque converter housing. The pump is gear driven off of the input flange to the torque converter. The pump is in operation when the engine is run.

The pump is a single section gear-type pump. Oil from the bottom of the transmission case goes into the pump through the inlet passage in base assembly (1). The oil fills the space between the gear teeth of drive gear (4) and idler gear (5). The gears turn, and the oil is sent out another passage in base assembly (1) to provide pressure for the hydraulic system.

Oil Filter

Pressure oil from the hydraulic pump goes through inlet passage (B) in filter housing (5). Oil fills the space between filter element (4) and the inside wall of housing (5). During normal operation, the oil goes through element (4) and then out through outlet passage (A). As the oil passes through the filter element, foreign particles are stopped and cannot go through the hydraulic system.

Oil Filter Construction 1. Spring. 2. Cover. 3. Bypass valve. 4. Filter element. 5. Filter housing. 6. Plug. A. Outlet passage. B. Inlet passage.

If filter element (4) becomes full of debris (clogged), oil can not go through. At this time, pressure oil moves bypass valve (3) against the force of its spring and the valve will open.

This lets the flow of oil bypass the element and go to the transmission without restriction.

Since the oil that goes through bypass valve (3) is not cleaned of debris, damage to other components in the hydraulic system will result.

Correct maintenance should be used to make sure that the filter element does not become full of debris (clogged) and stop the flow of clean oil to the hydraulic oil system.

Transmission Oil Cooler

Coolant from the engine comes in at the front end. The coolant goes through the many long tubes that are in the cooler. After the coolant goes through the tubes, it goes out through the other end of the cooler and returns to the engine cylinder block.

Transmission Oil Cooler (Schematic) 1. Oil cooler.

The flow of oil is around and along the many tubes inside the cooler. In this procedure, heat is removed from the oil and is given to the coolant of the engine. The engine coolant goes through the tubes inside the cooler and takes the heat from the oil. The coolant is then cooled by the cooling system of the engine.

After the oil goes along the tubes in the cooler, it goes out through a passage at the front and has a lower temperature. The oil then goes to the transmission for lubrication.

Transmission Hydraulic Controls - (Power Shift)

Transmission Hydraulic Controls Schematic (First Forward) 1. Selector valve body. 2. Priority valve. 3. Oil filter. 4. Speed selector valve spool. 5. Oil pump. 6. Directional selector valve spool. 7. Oil sump and screen. 8. Torque converter inlet relief valve spool. 9. Torque converter. 10. Pressure control valve body. 11. Oil cooler. 12. Orifice. 13. Transmission lubrication relief valve. 14. Load piston. 15. Modulating relief valve spool. 16. Differential valve spool. A. Speed clutch oil pressure tap (P1). B, C and D. Transmission pump oil pressure taps. E. Directional clutch oil pressure tap (P2). F. Torque converter outlet oil pressure tap. G. Torque converter inlet oil pressure tap (P3). H. Transmission lubrication oil pressure tap.

The basic components of the transmission hydraulic control oil system are oil screen, oil pump, oil filter, priority valve, transmission hydraulic controls, torque converter and oil cooler. The only oil lines outside the transmission case are those from the screen to the pump, pump to oil filter, oil filter to torque converter housing, and to an from the transmission oil cooler.

The hydraulic controls are made up of a selector valve group (1) and a pressure control valve group (10). The hydraulic controls are fastened to the top of the No. 2 and No. 3 clutch housing. The controls are completely enclosed by the transmission case. Three FORWARD and three REVERSE speeds are provided by the transmission and the hydraulic controls. The selector valve will send the oil to put pressure on the correct clutches for speed and direction. Pressures in the hydraulic system are controlled by the pressure control valve.

Operation

When the machine is started and the selector lever is in the NEUTRAL position, pressure oil from oil pump (5) goes through oil filter (3) and priority valve (2) to selector valve body (1). The pressure oil is then sent to modulating relief valve (15). The oil flows around the small diameter portion of the valve spool and enters the slug cavity end of the spool behind the poppet valve. The load piston cavity is open to drain, because the springs keep differential valve spool to the right. With the differential valve in this position, the oil pressure will be kept at initial pressure.

When a shift is made and a transmission clutch is opened to be filled, the system pressure will drop. The modulating relief valve spring will force modulating relief valve (15) to the right and stop the supply of oil to the torque converter. As the clutches fill, the system pressure will increase and force modulating relief valve (15) to move to the left and open the passage to the torque converter. Further increase in the system pressure will cause load piston (14) to move to the right and increase the spring force against modulating relief valve (15). This gradual increase of clutch pressure versus psi, is called modulation.

When full clutch pressure is reached, the speed clutch pressure is approximately 300 psi (2050 kPa) and directional clutch pressure is approximately 50 psi (345 kPa) less than speed clutch pressure. This pressure difference is controlled by differential valve spool (16).

Since the pressure is greater in the speed clutches, they engage first and the load is picked up by the directional clutches which have the lower pressure and therefore engage last.

If the engine is started when the selector lever is in any position but NEUTRAL, oil will flow to both ends of differential valve (16). The spring force will hold the valve spool to the right. In this position, the oil flow to the directional clutches is stopped and the machine will not move. When the selector lever is moved to the NEUTRAL position. The oil at the spring end of the differential valve is opened to drain. The oil pressure will force the spool to the left and the controls are ready for a clutch to fill and the modulation cycle as soon as the selector lever is moved to a speed position.

Torque converter inlet relief valve (8) controls the maximum pressure of the oil going to the torque converter.

The torque converter outlet oil pressure is controlled by orifice (12).

Parts of the transmission are pressure lubricated. The lubrication oil pressure is controlled by transmission lubrication relief valve (13). Lubrication oil pressure is approximately 12 psi (85 kPa).

Priority Valve

Priority Valve 1. Spool assembly. 2. Spring. 3. Plunger. 4. Spacers. 5. Spring. 6. Slug. 7. Inlet passage. 8. Passage to transmission control valve group.

The priority valve is fastened to the upper left side of the torque converter housing. The priority valve controls the minimum pressure to the steering clutch control valve. A minimum pressure of 250 psi (1720 kPa) must be available to operate the steering clutches. Spacers (4) control the minimum pressure, for psi change see the chart in the D4E Power Shift Transmission Testing and Adjusting, Form SENR7632.

Torque Converter and Transmission - (Power Shift)

The transmission is made up of a torque converter and a 3-speed forward, 3-speed reverse planetary gear transmission. The five clutches in the planetary group are hydraulically controlled. Each speed is manually selected.

The location of the single stage torque converter is at the input end of the transmission. The converter is fastened to the engine flywheel through a flexible coupling. Output torque from the converter goes to the planetary transmission through either the No. 1 or No. 2 sun gear. The engagement of a directional clutch sends the power through the respective sun gear.

The clutches of the planetary group are divided into two sections. Their identification is made according to their function. No. 1 and No. 2 clutches make-up the directional section. No. 3, No. 4 and No. 5 clutches make-up the speed clutch section. It is necessary for one clutch in each section to be engaged for each speed. The planetary group output shaft is connected to the bevel pinion.

Torque Converter

Oil for operation of the converter comes from the transmission oil pump. The converter inlet oil pressure is controlled by the inlet relief valve. The location of the valve is in the selector valve group.

Torque Converter 1. Stator carrier. 2. Impeller. 3. Turbine. 4. Stator. 5. Oil pump drive gear. 6. Oil inlet port. 7. Output shaft. 8. Oil outlet port. 9. Rotating housing.

An orifice in the converter outlet oil passage controls the outlet oil pressure.

The input flange, rotating housing (9), impeller (2), impeller hub and drive gear (5) for the oil pumps, turn as a unit at engine speed.

Flow Of Oil Through Torque Converter 2. Impeller. 3. Turbine. 4. Stator. 9. Rotating housing.

Oil from the transmission hydraulic controls, goes to the torque converter through an inlet port in stator carrier (1). Oil is sent to the stator carrier through a passage in the torque converter housing.

The impeller (2) works as a pump. It gives energy to the oil in the torque converter. The force of the oil drives turbine (3) which is connected to output shaft (7). The oil hits the blades of turbine (3) with force and makes the turbine turn. During light load conditions, the oil hits the turbine blades at a small angle. When a large resistance is felt, the speed of the turbine decreases through the load on output shaft (7) and the oil hits the turbine blades at a more direct angle. This action increases the torque of the output shaft.

The oil which goes thorugh the blades of turbine (3) is sent to impeller (2) by stator (4) and the cycle starts again.

Oil leaves the converter through an outlet passage in the stator carrier. The oil flows through an oil cooler and then to the transmission lubrication system.

Clutch Operation

The transmission has three speeds FORWARD and three speeds REVERSE. It has planetary gear systems and five hydraulic clutches.

Clutch Operation
(Typical Example) 1. Piston. 2. Spring. 3. Plates. 4. Ring gear. 5. Discs. 6. Clutch housing.

The five transmission clutches are the disc type and in separate housings. Each clutch has discs (5) and plates (3). The inside teeth of discs (5) are engaged with the outside teeth of ring gear (4). Notches on the outside diameter of plates (3) are engaged with pins in the clutch housing. The pins hold the plates stationary.

In the example above, springs (2) are between clutch housing (6) and piston (1). The springs keep the clutches disengaged (not engaged). The clutches are engaged when oil is sent into the area behind piston (1). When the pressure of the oil in the area behind the piston increases, the piston moves to the right. The piston moves against the force of spring (2) and pushes the discs and plates together. The clutch is now engaged. The discs hold ring gear (4) stationary. When the clutch is released, the pressure in the area behind piston (1) decreases and the force of spring (2) moves the piston to the left. The discs and plates are now apart. The clutch is not engaged.

Clutch Identification

The two front clutches (No. 1 and No. 2) are direction clutches. The No. 2 clutch is the FORWARD direction clutch. The No. 1 clutch is the REVERSE direction clutch. The three rear clutches (No. 3, No. 4 and No. 5) are speed clutches.

A speed and a direction clutch must be engaged in the transmission before power goes through the transmission.

Power Flow Through The Transmission

Transmission Components 1. Manifold assembly. 2. No. 5 clutch. 3. No. 5 clutch housing. 4. No. 4 carrier. 5. No. 5 clutch gear. 6. No. 4 clutch. 7. No. 4 planet gear. 8. No. 3 clutch. 9. No. 3 planet gear. 10. No. 2 clutch. 11. No. 2 planet gear. 12. No. 1 clutch. 13. No. 1 clutch ring gear. 14. No. 3 and No. 4 sun gear. 15. No. 1 carrier. 16. No. 1 planet gear. 17. No. 4 clutch ring gear. 18. No. 1 and No. 2 sun gear. 19. No. 3 carrier. 20. No. 4 clutch housing. 21. No. 3 clutch ring gear. 22. No. 2 and No. 3 clutch housing. 23. No. 2 clutch ring gear. 24. No. 1 clutch housing. 25. No. 2 carrier. 26. No. 1 and No. 2 carrier ring gear.

The directional clutch section is made up of the No. 1 and No. 2 clutches and No. 1 and No. 2 planetary carriers. The No. 1 clutch is the reverse directional clutch. The No. 2 clutch is the forward directional clutch. The No. 1 clutch ring gear and No. 1 carrier are connected together and turn as a unit. The No. 1 and No. 2 carrier ring gear, No. 2 and No. 3 carrier, and No. 4 carrier are connected together and turn as a unit. The speed clutch section is made up of the No. 3 (3rd speed), No. 4 (2nd speed) and No. 5 (1st speed) clutches and No. 3, No. 4 and No. 5 planetary carriers. The No. 4 clutch ring gear is connected to the No. 5 carrier. The No. 3 sun gear is a part of the output shaft. The No. 4 and No. 5 sun gears are connected to the output shaft.

In the illustrations that follow, circles give the indication that the clutches are engaged. The darker components are the components that move and send power through the transmission.

First Speed Forward

First Speed Forward
(No. 2 and No. 5 clutches engaged)

The No. 2 clutch ring gear is kept stationary. This will cause the No. 2, No. 3 and No. 4 carriers and No. 5 clutch to turn. The No. 5 clutch is also engaged. The torque will then go to the No. 5 clutch gear and output.

Second Speed Forward

Second Speed Forward
(No. 2 and No. 4 clutches engaged)

The No. 2 clutch ring gear is kept stationary. This will cause the No. 2, No. 3 and No. 4 carriers to turn. The No. 4 clutch ring gear is kept stationary by the engaged No. 4 clutch. The No. 4 planet gears move around the inside of the No. 4 clutch ring gear and drive the No. 4 sun gear. The No. 4 sun gear is connected to the No. 5 clutch gear and output.

Third Speed Forward
(No. 2 and No. 3 clutches engaged)

The No. 2 clutch ring is kept stationary by the No. 2 clutch. The No. 3 clutch ring gear is kept stationary by the No. 3 clutch. The No. 2 sun gear will drive the No. 2 planet gears which move around the inside of the No. 2 clutch ring gear and turn the No. 2 carrier. The No. 3 planet gears are driven around the inside of the stationary No. 3 clutch ring gear and drive the No. 3 sun gear, No. 5 clutch gear and output.

First Speed Reverse

First Speed Reverse
(No. 1 and No. 5 clutches engaged)

The No. 1 clutch ring gear and No. 1 carrier are kept stationary by the No. 1 clutch. The No. 1 sun gear will drive the No. 1 and No. 2 clutch ring gears through the No. 1 planet gears. This will cause the No. 2, No. 3 and No. 4 carriers and No. 5 clutch to turn in the opposite direction. The No. 5 clutch is also engaged, the torque will then go to the No. 5 clutch gear and output.

In second speed reverse, the No. 1 and No. 4 clutches are engaged. The power flow through the directional clutch section of the transmission is identical to first speed reverse. The power flow through the speed clutch section of the transmission is the same as for second speed forward.

In third speed reverse, the No. 1 and No. 3 clutches are engaged. The power flow through the directional clutch section is the same as for the first speed reverse. Power flow through the speed clutch section is the same as for third speed forward.

Hydraulic System - (Direct Drive)

Hydraulic Pump

The hydraulic pump is a two-section gear-type, drive by the flywheel clutch.

Hydraulic Pump Construction 1. Cover. 2. Body. 3. Manifold assembly. 4. Body. 5. Cover. 6. Gear. 7. Gear. 8. Gear. 9. Gear. A. Steering hydraulic section. B. Flywheel clutch lubrication section.

Gear (6) and gear (7) are driven by a gear in the flywheel housing. Gear (6) turns idler gear (8), while gear (7) turns idler gear (9). During operation, oil from the steering clutch and bevel gear case enter section (A) of the pump through a passage in cover (1). The oil fills the space between the gear teeth. The gears turn, and the oil is sent out another passage in cover (1) to supply pressure oil to the steering hydraulic system.

Flywheel clutch oil enters section (B) of the pump through a passage in manifold assembly (3). The oil fills the space between the gear teeth. The gears turn, and the oil is sent out of another passage in manifold assembly (3) to the flywheel clutch housing. Oil from section (B) will supply pressure oil to lubricate and cool the flywheel clutch.

The pump will operate whenever the diesel engine is in operation.

Magnetic Screen

The magnetic screen is located between the reservoir in the steering clutch and bevel gear case and the inlet to the hydraulic pump. Oil from the reservoir comes into the magnetic screen through the bottom. As the oil flows through the tube assembly toward the top, it goes through the opening, between the magnets. The magnets are installed on the tube assembly so that the same magnetic ends are next to each other.

As the oil goes over the magnets, metal particles are stopped and held by the magnets. The oil then goes through the screen on its way to the outlet. As the oil goes through the screen, other foreign particles are stopped and can not go into the hydraulic system. From the outlet, the oil is sent to the inlet port of the hydraulic oil pump.

Oil Filter

Oil Filter Construction 1. Cover assembly. 2. Bolts. 3. O-ring seal. 4. Bypass valve. 5. Spring. 6. Washer. 7. Filter element. 8. Retainer. 9. Seal. 10. Spring. 11. Filter housing. 12. Plug.

Pressure oil from the hydraulic oil pump goes in filter housing (11) through an inlet passage near the top of the housing.

Oil fills the space between filter element (7) and the inside wall of housing (11). During normal operation, the oil goes through element (7) and then goes out the bottom of the filter housing through the outlet tube. As the oil goes through the filter element, foreign particles are stopped, and can not go through the hydraulic system.

If filter element (7) becomes full of debris (clogged), oil can not go through. At this time, pressure oil moves bypass valve (4) against the force of its spring and the valve will open. The open valve allows the oil to flow through the outlet tube and into the system without restriction.

Since the oil that flows through bypass valve (4) is not cleaned of debris, damage to components in the hydraulic system will result.

Correct maintenance should be used to make sure that the filter element does not become full of debris (clogged) and stop the flow of clean oil to the hydraulic oil system.

Flywheel Clutch - (Direct Drive)

The flywheel clutch is operated manually and is an oil-type. The flywheel clutch sends the torque from the engine through the universal joint to the transmission.

Two drive discs (10) and drive plate (4) send torque through the flywheel clutch. The action of a cam link and roller assembly against a plate keeps the flywheel clutch engaged. A brake on the clutch shaft is activated when the clutch is released. When the flywheel clutch is fully released, the rotation of the clutch shaft and the upper shaft of the transmission is stopped.

Flywheel Clutch 1. Clutch shaft brake drum. 2. Oil pump drive gear. 3. Sliding collar assembly. 4. Drive plate. 5. Plate. 6. Clutch hub. 7. Cam link and roller assemblies (four). 8. Clutch shaft. 9. Yoke assembly. 10. Driven discs (two).

Drive plate (4) has teeth on the outer edge. The teeth are engaged with teeth on the inside of the engine flywheel. Driven discs (10) have teeth on the inside edge. The teeth are engaged with teeth on the outside of hub (6). Splines connect hub (6) to clutch shaft (8). One end of clutch shaft (8) is a drive flange. The drive flange is connected to the universal joint. The universal joint is connected to the upper shaft of the transmission. Dirt is kept out of the clutch housing by a lip-type seal in the clutch housing. The seal also keeps oil in the clutch housing. The drive flange end of the clutch shaft is held by a bearing. Hub (6) is held in the center of the engine flywheel by a bearing.

Operation

When the flywheel clutch lever is moved to the ENGAGED position, yoke assembly (9) moves collar assembly (3) to the right. Collar assembly (3) is connected to cam link and roller assemblies (7). Cam link and roller assemblies (7) push against plate (5). Plate (5) pushes against driven discs (10) and drive plate (4). Driven discs (10) make contact with drive plate (4). The friction between drive plate (4) and driven discs (10) causes the driven discs to turn. The driven discs turn hub (6). Hub (6) turns clutch shaft (8). Clutch shaft (8) turns the universal joint. The clutch is held ENGAGED by the action of cam link and roller assemblies (7).

When the flywheel clutch lever is moved to the NOT ENGAGED position, yoke assembly (9) pulls collar assembly (3) to the left. The movement of collar assembly (3) releases the action of cam link and roller assemblies (7). Plate (5) no longer pushes against driven discs (10) and drive plate (4). Springs move plate (5) to the left. The driven discs are no longer in contact with the drive plate. The drive plate does not turn the driven discs. Power can not go through the flywheel clutch to the transmission.

After the flywheel clutch is NOT ENGAGED, the clutch shaft can be stopped by further movement of the clutch lever. At this time, the brake lining on the control lever makes contact with brake drum (1) on the clutch shaft. The movement of clutch shaft (8) is stopped.

Lubrication

The oil pump is fastened to the clutch housing. When the engine is in operation, the flywheel turns plate (5). Plate (5) turns gear (2). Gear (2) turns a gear on the oil pump, and the oil pump turns.

The oil pump pulls oil from the reservoir in the bottom of the flywheel housing through a passage and screen. The oil goes through passages in the clutch shaft for lubrication of the inside components. The driven discs and drive plates get lubrication from oil thrown by the clutch shaft and the clutch hub. Passages in clutch hub (6) let oil go to the pilot bearing in the flywheel.

Gearshift And Interlock Mechanism - (Direct Drive)

There are two transmission shift control levers and one flywheel clutch control lever to control the gear shift and interlock mechanism. The two transmission control levers are fastened to the top of the transmission case.

Gearshift Control Group
(VIEWED FROM RIGHT) 1. Forward-reverse shift lever. 2. Speed selector lever. 3. First and second speed shifter fork. 4. Third and fourth speed shifter fork. 5. Fifth speed shifter fork. 6. Forward-reverse shifter fork.

Movement of levers (1) and (2) to different positions will give a selection of five FORWARD and five REVERSE speeds. The forward or reverse direction selection is made by forward-reverse shift lever (1), while the desired speed selection is made with speed selector lever (2).

Gearshift Control Group
(VIEWED FROM FRONT) 1. Forward-reverse shift lever. 2. Speed selector lever. 3. First and second speed shifter fork. 4. Third and fourth speed shifter fork. 5. Fifth speed shifter fork. 6. Forward-reverse shifter fork. 7. Interlock shaft. 8. Shifter shafts (four).

Forward-reverse shifter fork (6) is controlled by lever (1). Shifter forks (3), (4) and (5) are controlled by lever (2).

When flywheel clutch lever (9) is moved to the ENGAGED POSITION, rod (10) will move interlock shaft (7) of the interlock mechanism.

The interlock mechanism, attached to the gear shift housing, holds the shifter forks and transmission gears in position when the clutch is ENGAGED.

The interlock mechanism consists of spring-loaded plungers, which fit into notches on shifter shafts (8), and an interlock shaft (7) which is connected by a lever and rod to flywheel clutch control lever (9).

The cam on the interlock shaft locks the plungers in the notches on the shifter shafts when the flywheelclutch is ENGAGED, this holds the transmission gears so that they will not slide out of position. When the clutch is DISENGAGED, the interlock shaft is turned, and the plungers can then go out of the notches as the gears are shifted. Only a small load, made by the spring-loaded plungers, is needed to make a shift change.

Flywheel Clutch And Interlock Linkage 7. Interlock shaft. 9. Flywheel clutch control lever. 10. Interlock linkage rod.

Transmission - (Direct Drive)

Transmission Gear Arrangement 1. Upper countershaft. 2. Bevel pinion shaft. 3. Lower countershaft. A. First speed gear. B. Second speed gear. C. Third speed gear. D. Fourth speed gear. E. Fifth speed gear. F. Forward and reverse sliding gear. G. First speed sliding gear. H. Pinion gear. I. Second speed sliding gear. J. Third speed sliding gear. K. Fourth speed sliding gear. L. Fifth speed sliding gear. M. Reverse drive gear. N. Reverse idler gear.

The direct drive transmission is a sliding gear type, enclosed in a case by itself. Two levers are provided in the operator's compartment to obtain the desired speed and direction. The transmission has five speeds FORWARD and five speeds REVERSE. One lever controls the forward-reverse shifter fork, while the other lever controls the speed selection shifter forks. See the subject "GEAR SHIFT AND INTERLOCK MECHANISM," for explanation of shifter fork and control levers operation.

The interlock mechanism, actuated by the flywheel clutch control lever locks the sliding gears in position when the flywheel clutch is ENGAGED.

NOTE: Reverse gear (N) is always in mesh with reverse idler gear (H).

The chart that follows gives power flow through the transmission for each speed.

Location Of Transmission Shafts
AS SEEN FROM FRONT OF TRANSMISSION 1. Upper countershaft. 2. Bevel pinion shaft. 3. Lower countershaft.

Steering Clutches, Brakes And Final Drives

Steering Clutches And Final Drives

The main components of the steering clutches and final drives are: bevel gear (1), release bearing assembly (2), pressure plate assemblies (3), disc assemblies (7), steering clutch driving drum (4), steering clutch driver drum (14) [also the brake drum], final drive pinion (9), final drive gear (11), sprocket shaft (15) and sprocket (12).

The bevel gear and steering clutches are in the bevel gear and steering clutch case. The bevel gear case is the reservoir for the steering hydraulic system on the direct drive machines. On power shift machines, the transmission is the reservoir for the steering hydraulic system. As the bevel gear turns, lubricant is thrown on the bevel gear, bevel pinion and steering clutches for lubrication and cooling.

Steering Clutch 1. Bevel gear. 2. Release bearing assembly. 3. Pressure plate assembly. 4. Steering clutch driving drum. 5. Driving disc. 6. Springs. 7. Disc assemblies.

The bevel pinion shaft in the transmission turns the bevel gear. The ends of the bevel gear shaft are connected into the hub of a steering clutch driving drum. Bevel gear (1) is fastened to the bevel gear shaft. Springs (6) force pressure plate assembly (3) driving disc (5) and disc assembly (7) against driving drum (4).

The clutches are held engaged by spring force against the pressure plate assembly. This compresses the clutch plates between the pressure plate and flange on the driving drum. When the clutches are engaged, the bevel gear shaft, driving disc (5), steering clutch driven drum (14) and final drive pinion (9) turn as a unit. Power is sent to final drive sprocket (12) through the final drive gear and hub (11) in the final drives.

When the steering clutch is not engaged, release bearing assembly (2) is moved toward bevel gear (1) by mechanical linkage from the hydraulic steering booster. This moves the pressure plate out of contact with the clutch discs and the clutch is not engaged.

Contracting band-type brakes are used to add to the action of the steering clutches and to stop the machine.

Final Drive 8. Final drive pinion flange. 9. Final drive pinion. 10. Final drive cover. 11. Final drive gear and hub assembly. 12. Sprocket. 13. Duo-Cone seals. 14. Steering clutch driven drum. 15. Sprocket shaft. 16. Outer bearing adjusting nut. 17. Bearing support assembly.

Steering Clutch Control Linkage

Steering Clutch Control Linkage 1. Cylinder. 2. Piston assembly. 3. Relief valve (direct drive only) (earlier). 4. Control valve. 5. Handle. 6. Dash. 8. Tube assembly. 9. Yoke assembly. 10. Bellcrank. 11. Relief valve (direct drive only) (later).
Arrows show indication of movement of components when controls are activated).

When handle (5) is moved toward the rear of the machine (pulled out), the control linkage also will move (follow arrows). Bellcrank (10) will push stem (7) in on control valve (4). Stem (7) will put force on spring (14) and move spool (13) to the left. With the spool moved all the way to the left, pressure oil from the pump will enter passage (B) from passage (A).

When handle (5) is released, spring (14) will force stem (7) to the right and move the control linkage back to the engage position. Spring (12) will force spool (13) to the right and stop the flow of oil to passage (B).

Pressure oil from control valve (4) goes into cylinder (1) through tube assembly (8). The pressure will force the piston assembly to the right (front) and move bellcrank (17) against stop (16). Bellcrank (17) is connected to yoke assembly (9) by end (19) and nut (18). The movement of the bellcrank will pull the yoke assembly to the inside and disengage the steering clutch. When handle (5) is released and the oil pressure to cylinder (1) is stopped, the springs in the steering clutch will pull the yoke assembly back to the engaged position.

Steering Control Valve 7. Stem. 12. Spring. 13. Spool. 14. Spring. A. Inlet passage from the oil pump. B. Outlet pasage to cylinder assembly.

Steering Clutch Control Linkage (Top View) 9. Yoke assembly. 15. End. 16. Stop. 17. Bellcrank. 18. Nut. 19. End.

Steering Clutch Relief Valve (Direct Drive Only) (Earlier)

Steering Clutch Relief Valve 1. Passage (inlet). 2. Seat. 3. Spring. 4. Plug. 5. Valve.

The relief valve is part of the steering control valve for the steering clutches. The relief valve controls the pressure of the oil that goes in the steering control valve. The pressure of this oil is approximately 300 psi (2050 kPa). The extra oil will return to the bevel gear case. The minimum pressure needed to operate the steering clutches is 230 psi (1585 kPa).

Steering Clutch Relief Valve (Direct Drive Only) (Later)

1. Spring. 2. Slug. 3. Piston. 4. Valve. 5. Inlet passage from the oil pump. 6. Outlet passage to bevel gear case (drain).

The relief valve is part of the steering control valve for the steering clutches. The relief valvecontrols the pressure of the oil that goes in the steering control valve.

When the steering clutches are engaged valve (4) is moved from its seat and keeps the pressure of oil at passage (5) at approximately 100 psi (690 kPa) and lowers the horsepower requirements to operate the oil pump. Pressure oil that goes around valve (4) is sent to passage (6).

When a steering clutch is disengaged the pressure oil that comes in passage (5) is moved through the steering control valve to the oil line that goes to the top of the relief valve and to the cylinder that disengages the steering clutch. The pressure oil that comes in the top of the relief valve moves slug (2) that keeps the oil flow to the side of the disengaged clutch. The pressure oil then moves piston (3) down against spring (1) and closes valve (4). This increases the pressure of the oil to a maximum of approximately 300 psi (2050 kPa). The increase in oil pressure moves the oil flow out of the top of the relief to the oil line that goes to the cylinder that disengages the steering clutch. The minimum pressure needed to operate the steering clutches is 230 psi (1585 kPa).

Brakes

Two band-type brakes, one on each steering clutch drum, stop the movement of the machine. The brakes also give assistance to the steering clutches to turn the machine. The operation of each brake is separate from the other. Both brakes can be held in the "ON" position by pawl (1) of the parking brake linkage.

Brake Control Linkage 1. Parking brake pawl. 2. Parking brake control lever. 3. Brake pedal. 4. Spring. 5. Brake adjusting nut. 6. Brake band.
(NOTE: Arrows show indication of movement of components when the brakes are applied.)

The operation of both brakes is the same. When brake pedal (3) is pushed forward, the linkage is activated [follow arrows from pedal (3)]. The movement of the linkage will cause brake band (6) to make contact with the steering clutch driven drum.

When the brake pedal is released, spring (4) releases the pressure on the drum.

To engage the parking brake, push forward on one or both of the brake pedals and push lever (2) down. This causes pawl (1) to make contact with the parking brake linkage. To release the parking brake, push both pedals fully forward and pull lever (2) up.

Undercarriage

The undercarriage connects to the body and final drives. Two track assemblies are kept in parallel alignment by the diagonal braces of the track roller frames. Each track assembly can move up and down by itself.

The components of the undercarriage are: equalizer bar, track rollers, track carrier rollers, tracks, front idlers, track roller frames, track adjusters and recoil springs.

The front idlers, track rollers and track carrier rollers use Duo-Cone seals to prevent the loss of lubricant and to keep out foreign material.

Track Roller Frames

The track roller frames are fastened to the final drive bearing cage and to the steering clutch and bevel gear case. The parallel alignment of the track roller frames is kept by diagonal braces. Each roller frame can move up and down by itself.

The track rollers, track carrier rollers, front idlers, track adjusters and recoil springs are fastened to the track roller frames.

The alignment of the track roller frames and final drives is controlled by the shim adjustment of the final drives.

Track Carrier Rollers

The track carrier rollers give support to the track between the sprocket and the front idler. The shaft of the track carrier roller is fastened to a support bracket by a clamp. The support bracket is fastened to the track roller frame.

Track Carrier Roller 1. Shaft. 2. Duo-Cone seal. 3. Bearings. 4. End cover. 5. Plug.

The track carrier rollers must be in alignment with the sprocket and the front idler. The alignment is done by the movement of the roller shaft inside the support bracket. The carrier rollers turn on two tapered roller bearings.

Track Carrier Roller Lubrication

If lubricant is added with the roller removed from the machine, shaft (1) must be in a horizontal position.

Lubricant is sent into center of end cover (4) through the 5M2080 Nozzle. The lubricant fills the cavity between shaft (1) and the roller. When the cavity is full, the pressure of the oil causes the air and extra lubricant to go out the relief threads in the nozzle.

When the lubricant does not have any bubbles, remove the nozzle and install the plug. Tighten the plug to a torque of 125 ± 15 lb. ft. (170 ± 20 N·m).

Track Rollers

The track rollers are fastened to the track roller frames. The track rollers are in contact with the inside surfaces of the track links. Flanges on the track rollers prevent the movement of the track from side to side. The inside surfaces of the track links cause an equal distribution of the weight of the machine along the track.

The flange at the center of shaft (5) gets the side load on the roller. Bearings (3) also get the side load on the roller. The amount of side movement or end clearance of the shaft can not be adjusted.

The track rollers have Duo-Cone floating seals (6) at both ends of shaft (5).

Track Roller 1. Lock. 2. Inner end collar. 3. Bearings. 4. Outer end collar. 5. Shaft. 6. Duo-Cone seals. 7. Track roller.

Each track roller frame has five track rollers. The installation of the track rollers is as follows: 1. Start at the front of the machine and install two double flange rollers. 2. Then install one single flange roller. 3. Then install one double flange roller. 4. Then install one single flange roller.

Track Roller Lubrication

If lubricant is added with the roller removed from the machine, shaft (1) must be in a horizontal position. The slot, in the end where the 5M2080 Nozzle is installed, must be down.

Track Roller 1. Shaft. 2. Duo-Cone seals. 3. Plug. 4. Reservoirs. 5. Center passage.

Lubricant is sent into center passage (5) through the 5M2080 Nozzle. The lubricant fills the reservoirs (4) in the rollers. When the reservoirs are full, the pressure of the oil causes the air and extra lubricant to go out the relief threads on the nozzle.

When the lubricant does not have any bubbles, remove the nozzle and install the plug. Tighten the plug to a torque of 125 ± 15 lb. ft. (170 ± 20 N·m).

Front Idlers

The front idlers put the tracks in position in front of the track rollers. They also keep the tracks in alignment with the sprockets.

The adjustment of the tracks is done by the movement of the front idlers. The track adjusters move the front idlers and hold them in position.

The position of the front idlers is controlled by shims. The front idlers must have correct alignment with the track roller frames.

Front Idler 1. Shims. 2. Duo-Cone seals. 3. Bearings. 4. Passage. 5. Shaft. 6. Track roller frame. 7. Idler. 8. Plug.

Front Idler Lubrication

If lubricant is added with the idler removed from the machine, the shaft (5) must be in a horizontal position.

Lubricant is sent through the 5M2080 Nozzle into the center passage (4). The lubricant fills reservoirs around shaft (5). When the reservoirs are full, the pressure of the oil causes the air and extra lubricant to go out the relief threads in the nozzle.

When the lubricant does not have any bubbles, remove the nozzle and install plug (8). Tighten the plug to a torque of 125 ± 15 lb. ft. (170 ± 20 N·m).

Recoil Springs And Mechanisms For Track Adjustment

The recoil springs are normally in compression. They are held between brackets and stops on the track roller frames. Normally, the force of the springs is not against the tracks. The force against the track for the correct setting of track curve is controlled by the mechanism for track adjustment.

Recoil Spring And Mechanism For Track Adjustment 1. Springs. 2. Cavity. 3. Fill valve. 4. Recoil rod. 5. Nut. 6. Bolt. 7. Piston. 8. Pilot.

Track adjustment is made by the hydraulic mechanism for track adjustment. Pressure grease is sent to cavity (2) through a fill valve. This moves recoil rod (4) and the front idler toward the front of the machine. The movement of the recoil rod and front idler tightens the track. The tension on the track is released by a relief valve.

Show/hide table

Never visually inspect the vent holes or valves to see if grease or oil is coming out of them. Make sure the vent holes are clean before the tension is released on the track. Watch the cylinder to see that it moves.

If rocks or debris get between the track and the rollers, idler or sprocket, recoil rod (4) moves toward the rear of the machine. The movement of the recoil rod tightens the track. Since the grease in cavity (2) can not be put in compression, piston (7) and bolt (6) move toward the rear of the machine. Bolt (6) pushes pilot (8) toward the rear of the machine. Pilot (8) pushes on springs (1). This puts springs (1) in compression. The movement of pilot (8) and the compression of spring (1) prevent too much tension on the track.

Nut (5) is used to keep recoil spring in compression when it is installed in the machine.

Track

The machine has Sealed and Lubricated track.

Show/hide table

Secure track with chain before separating links. Sealed and lubricated track is very flexible. When disconnected it can move and cause injury.

Each track assembly has links, pins, bushings, thrust rings, polyurethane seal assemblies, rubber stoppers and polyurethane plugs.

Each of the track links (1) and (5) makes a fit over the track links in front of them. Link (1) makes a fit over link (13). Link (5) makes a fit over link (14). The connection of the track links makes the track assembly.

Track Assembly (Section) 1. Link. 2. Bushing. 3. Hole. 4. Hole. 5. Link. 6. Seal assembly. 7. Seal assembly. 8. Rubber stopper. 9. Polyurethane plug. 10. Pin. 11. Thrust ring. 12. Thrust ring. 13. Link. 14. Link.

Each link has a counterbore in the end which makes a fit with the link in front of it. Seal assemblies (6) and (7) are installed in the counterbores of the links. Each seal assembly has a load ring and a seal ring. The load ring pushes the seal ring against the end of bushing (2) and the link counterbore. The seal rings give a positive seal between the bushing and the link counterbore. The edge of the seal ring is against the end of the bushing. Thrust rings (11) and (12) are installed on pin (10). the thrust rings give a specific amount of compression to the seal assemblies and control the end play (free movement) of the joint. The arrangement of the seal assemblies and thrust rings keeps foreign materials out of the joint and oil in the joint.

Pin (10) has a hole (4) almost the full length of the pin. Hole (3) is drilled radially in the pin near the center of the pin. Radial hole (3) lets oil go to the surface between pin (10) and bushing (2) and to the lip of the seal rings. The oil gives lubrication to the pin and bushing and also makes the lip of the seal ring wet. The lip of the seal ring must be kept wet to prevent wear of the lip of the seal ring. Oil is kept in the pin by stopper(8) and plug (9). The oil is installed in the pin through a hole in the center of stopper (8). When the chambers in the pin are filled, plug (9) is installed in stopper (8).

Each pin and bushing assembly is sealed and has its own lubrication, the result is no internal wear on the joint. The interval for the turning of the track pins and bushings is much longer because the only wear will be on the outside of the bushings and the links.

Two piece master links (17) and master shoe (15) are held together with bolts (16).

Master Link And Master Shoe 15. Master shoe. 16. Bolts. 17. Master link.