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| Illustration 1 | g03729688 |
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(1) Gear Pump (two-section)
(1A) Controls Flow (High Pressure) (1B) Converter Charging Flow (Low Pressure) (1C) Pump purge Orifice (2) Oil Filter (Transmission) (2A) Pump Pressure (Machine Test Location) (3) Control Group (Transmission Hydraulics) (3A) Valve Group (Control) (3B) Solenoid for Clutch 1 (3C) Solenoid for Clutch 2 (3D) Total Clutch Leakage (Max) (3E) Valve Group (Control) (3F) Solenoid for Clutch 3 (3G) Solenoid for Clutch 4 (3H) Valve Group (Control) (3J) Solenoid for Clutch 5 (3K) Solenoid for Clutch 6 (4) Valve Group (Control) (4A) Electronic Main Relief Valve (4B) Pump Pressure (4C) Transmission Oil Temperature (4D) Solenoid for Lock-up Clutch (4E) Torque Converter Inlet Pressure (5) Lube (Pump Dive) (6) Torque Converter (6A) Torque Converter (Leakage) (6B) Torque Converter Outlet Pressure (6C) Torque Converter Temperature (6D) Valve - Relief (Torque Converter Inlet) (7) Cooler Group (Transmission) (8) Transmission (8A) Lube Pressure (8B) Transmission Lube (8C) Screen Assembly Tube Assembly -Magnetic | |
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| Illustration 2 | g03729718 |
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(1) Oil pump (transmission)
(1A) Controls Flow (High Pressure) (1B) Converter Charging Flow (Low Pressure) | |
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| Illustration 3 | g03729655 |
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(9) Transmission output speed sensor (2)
(10) Transmission output speed sensor (1) (11) Intermediate speed sensor (12) Torque converter output speed sensor (3A) Valve Group (Control) (3B) Solenoid for Clutch 1 (FWD LOW) (3C) Solenoid for Clutch 2 (FWD HI) (3E) Valve Group (Control) (3F) Solenoid for Clutch 3 (REV) (3G) Solenoid for Clutch 4 (Second) (3H) Valve Group (Control) (3J) Solenoid for Clutch 5 (Third) (3K) Solenoid for Clutch 6 (First) (4) Valve Group (Control) (4A) Electronic Main Relief Valve (4D) Solenoid for Clutch 7 (Lock-up) | |
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| Illustration 4 | g03729647 |
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(13) Gear
(14) Hub assembly (15) Input shaft assembly (16) Clutch 1 (17) Gear (18) Clutch 2 (19) Speed sensor (20) Gear (21) Hub assembly (22) Shaft assembly (23) Gear (24) Gear (25) Hub assembly (26) Gear (27) Gear (28) Gear (29) Gear (30) Clutch 4 (second speed) (31) Gear (32) Shaft assembly (33) Gear (34) Hub assembly (35) Hub assembly (36) Clutch 3 (reverse) (37) Gear (38) Gear (39) Hub assembly (40) Shaft assembly (41) Clutch 6 (first speed) (42) Gear (43) Clutch 5 (third speed and fourth speed) (44) Wave spring (45) Balance seal assembly (46) Output shaft assembly (47) Sump | |
The transmission ECM determines the proper clutches to be engaged. The proper clutch engagement is based on the inputs to the machine ECM. Some of the inputs that are considered are machine speed, engine speed, and operator inputs.
When the engine is started, the transmission oil pump (1) pulls oil from the sump (47). Transmission oil pump sends pump oil through two outlets. Control pressure flow and converter charging flow (1A). Control pressure flow (1B) passes through transmission oil filter (2). Control pressure oil flows from the transmission oil filter to the oil inlet in the transmission housing. The control pressure oil flows through an internal passage of the transmission housing. The oil then flows to the transmission control group (3). The control pressure oil flows into the following control valves: (3A), (3E), (3H) and 4.
The transmission electronic main relief valve (4A) controls the pressure of the control pressure oil that is supplied to the clutch valve groups. Control pressure flow not used by the clutches passes through the electronic main relief valve to the torque converter inlet. Converter charging flow (1B) oil flows to the torque converter inlet and joins with the oil flow through the electronic main relief valve. The combined oil is directed to the torque converter (6) and lube oil (5) for the pump drive. Torque converter outlet oil flows through torque converter outlet relief valve (6B) to oil cooler (7). After the oil cools, the oil flows through the lubrication system (8B) and to the sump (47).
Torque converter inlet relief valve (6D) limits the torque converter inlet oil pressure in order to protect the torque converter.
Table 1 gives the combination of the clutches that are engaged for each forward and each reverse speed. There is a modulating valve for each clutch. The modulating valve directs pressurized oil to the clutch in order to engage the clutch. A solenoid is located on each modulating valve. The solenoid controls the modulating valve spool. The transmission ECM controls the solenoids.
| First speed forward | Second speed forward | Third speed forward | Fourth speed forward | Fifth speed forward | Neutral | First speed reverse | Second speed reverse | Third speed reverse | |
| Clutch 1 (forward low) | X | X | X | ||||||
| Clutch 2 (forward high) | X | X | |||||||
| Clutch 3 (reverse) | X | X | X | ||||||
| Clutch 4 (second speed, third speed) | X | X | X | ||||||
| Clutch 5 (third speed, fourth speed, fifth speed, and Neutral) | X | X | X | X | |||||
| Clutch 6 (first speed) | X | X |
The countershaft transmission is a power shift transmission that has five forward speeds and three reverse speeds. The transmission has six clutches that are engaged hydraulically. All clutches are disengaged by wave spring (44) and balance seal assembly (45). The balance seal assembly neutralizes the pressure caused by rotation.
Balance seal assembly (45) and wave spring (44) are assembled inside the clutch piston. When the clutch is disengaged, force from wave spring (44) and pressure from lube oil will move the clutch piston to the disengaged position.
The transmission has five shafts: Input shaft assembly (15), output shaft assembly (46), and three gear shaft assemblies. Input shaft assembly (15) is driven by the torque converter turbine. Shaft assembly (22) contains clutch 1 (16) (forward low) and clutch 2 (18) (forward high). Shaft assembly (32) contains clutch 3 (10) (reverse) and clutch 4 (30) (second speed). Shaft assembly (40) contains clutch 5 (43) (third speed and fourth speed) and clutch 6 (41) (first speed).
Each of the three transmission shafts that carry clutches have three internal oil passages. One passage is for carrying the oil for the lubrication and cooling of the clutches, bearings, and gears. The other two passages are for carrying pressure oil for the engagement of the clutches on each shaft.
In order to transfer power through the transmission, a speed clutch and a direction clutch must be engaged.
The transmission ECM determines the proper clutches to be engaged. The proper clutch engagement is based on the inputs to the machine ECM. Some of the inputs that are considered are machine speed, engine speed, and operator inputs.
The transmission electronic control module (ECM) modulates the electrical current that is sent to the selected clutch solenoids. The clutch solenoids are located on the modulating relief valves. Modulating the current to the clutch solenoid controls the clutch pressure by shifting the spool in the modulating valve.
When the transmission direction and speed control lever is moved to the FIRST SPEED FORWARD position, both solenoid (3K) on modulating valve for clutch 6 (41) (first speed) and solenoid (3B) on modulating valve for clutch 1 (16) (forward low) are energized. When the solenoid (3B) for modulating valve clutch 1 (16) is energized, the modulating valve directs pump oil to clutch 1 (16) to engage clutch. When the solenoid for modulating valve clutch 6 (41) is energized, the modulating valve directs oil to clutch 6 (41) in order to engage the clutch.
The oil in the clutches that are not engaged is sent back to sump (47).
The transmission electronic main relief valve (4A) controls the pressure of the pump oil that is supplied to the modulating valves. The transmission electronic main relief valve (4A) directs the unneeded pump oil to the torque converter (6) as torque converter oil. Torque converter outlet oil flows through torque converter to oil cooler (7). After the oil cools, the oil flows to the transmission for lubrication (8B). After the transmission is lubricated and oil is cooled, the oil flows to the sump (47).
Torque converter inlet relief valve (6D) limits the torque converter inlet oil pressure in order to protect the torque converter.
When the transmission ECM determines that the transmission should be in NEUTRAL, clutch 5 (third speed) is engaged.
The transmission electronic control module (ECM) modulates the electrical current that is sent to the selected clutch solenoids. The clutch solenoids are located on the modulating relief valves. Modulating the current to the clutch solenoid controls the clutch pressure by shifting the spool in the modulating valve.
When the transmission direction and speed control lever is moved to the NEUTRAL position or the transmission neutralizer is activated, the solenoid for modulating valve clutch 5 (3J) is energized. When the solenoid for modulating valve clutch 5 (3J) is energized, the modulating valve directs the pump oil to clutch 5 (43) to engage clutch.
The oil in the clutches that are not engaged is sent back to sump (47).
The transmission electronic main relief valve (4A) controls the pressure of the pump oil (1) that is supplied to the modulating valves. The transmission electronic main relief valve (4A) directs unneeded pump oil to the torque converter (6). Torque converter outlet oil flows to oil cooler (7). After the oil cools, the oil flows to the transmission for transmission lubrication. After the transmission is lubricated and cooled, the oil flows to the sump (47).
Torque converter inlet relief valve (6D) limits the torque converter inlet oil pressure in order to protect the torque converter.
The transmission ECM determines the proper clutches to be engaged. The proper clutch engagement is based on the inputs to the machine ECM. Some of the inputs that are considered are machine speed, engine speed, and operator inputs.
The transmission electronic control module (ECM) modulates the electrical current that is sent to the selected clutch solenoids. The clutch solenoids are located on the modulating relief valves. Modulating the current to the clutch solenoid controls the clutch pressure by shifting the spool in the modulating valve.
When the transmission direction and speed control lever is moved to the FIRST SPEED REVERSE position, both the solenoid on the modulating valve for clutch 6 (3K) (first speed) and the solenoid on the modulating valve for clutch 3 (3F) (reverse) are energized. When the solenoid for modulating valve clutch 3 (3F) is energized, the modulating valve directs pump oil to clutch 3 (36) to engage clutch. When the solenoid for modulating valve clutch 6 (3K) is energized, the modulating valve directs pump oil to clutch 6 (41) to engage clutch.
The oil in the clutches that are not engaged flows to sump (47).
The transmission electronic main relief valve (4) controls the pressure of the pump oil (41) that is supplied to the modulating valves. The transmission electronic main relief valve (45) directs the unneeded oil to the torque converter (6). Torque converter outlet oil flows to oil cooler (7). After the oil cools, the oil flows to the transmission for transmission lubrication. After the transmission is lubricated and cooled, the oil drains to the sump (47).
Torque converter inlet relief valve (6D) limits the torque converter inlet oil pressure in order to protect the torque converter.