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Personal injury or death can result from sudden machine movement. Sudden movement of the machine can cause injury to persons on or near the machine. Prevent possible injury by performing the procedure that follows before working on the machine. |
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| NOTICE |
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Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to Special Publication, NENG2500, "Caterpillar Tools and Shop Products Guide" for tools and supplies suitable to collect and contain fluids on Caterpillar products. Dispose of all fluids according to local regulations and mandates. |
- Park the machine on a smooth, level surface.
- Shift the transmission direction control switch to the NEUTRAL position.
- Lower the work tool to the ground.
- Engage the parking brake.
- Place blocks in front of the wheels and behind the wheels.
- Install the steering frame lock.
- Remove the front axle shafts and rear axle shafts except for stall tests.
- Allow only authorized personnel on the machine. Keep unauthorized personnel off the machine and in clear sight of the operator.
Note: All tests and all adjustments must be made while the transmission oil is at normal operating temperature.
| NOTICE |
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Do not connect or disconnect hose fittings to or from the quick disconnect nipples when there is pressure in the system. This will prevent damage to the seals that are in the fitting. |
| Required Tools | ||
| Part Number | Description | Qty |
| 1U-5481 | Pressure Gauge Group | 1 |
| 1U-5482 | Pressure Adapter Group | 1 |
Diagnostic Testing of the Transmission Electronic Control
The electronic control module (ECM) for the transmission is located behind the cover panel at the right rear of the cab. The main function of the ECM is shifting the transmission. The ECM receives information from the transmission controls and the auto/manual switch in order to shift the transmission to the desired speed and direction.
The ECM also controls the starting of the engine and the backup alarm. The ECM will not allow the engine to be started unless the direction control switch is in the NEUTRAL position. The backup alarm is activated when the direction control switch is in the REVERSE position.
The ECM has a built-in diagnostic system in order to detect faults in the electronic system of the transmission. The diagnostic information is displayed on the electronic display module, when the system is placed in the service mode.
Test Procedures
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| Illustration 1 | g00873827 |
Transmission Hydraulic Control in the NEUTRAL position and with the Engine Stopped. (1) Transmission hydraulic control relief valve (2) Torque converter inlet relief valve (3) Torque converter (4) Torque converter outlet relief valve (5) Transmission oil filter (6) Clutch solenoid modulating valve for the Number 1 clutch (7) Clutch solenoid modulating valve for the Number 4 clutch (8) Clutch solenoid modulating valve for the Number 2 clutch (9) Clutch solenoid modulating valve for the Number 5 clutch (10) Clutch solenoid modulating valve for the Number 3 clutch (11) Clutch solenoid modulating valve for the Number 6 clutch (12) Transmission oil pump (13) Suction screen and magnet (14) Oil sump (15) Transmission lubrication (16) Oil cooler (A) P3 Torque converter inlet pressure tap (B) Torque converter outlet pressure tap (C) Pump pressure tap at the oil filter (D) Pressure tap for the Number 1 clutch (E) Pressure tap for the Number 4 clutch (F) Pressure tap for the Number 2 clutch (G) Pressure tap for the Number 5 clutch (H) Sampling valve for the transmission oil (J) Pressure tap for the Number 3 clutch (K) Pressure tap for the Number 6 clutch (L) Transmission lubrication pressure tap | |
| Transmission Pressures (1) | ||||
| Pressure | Pressure Tap | Position of Governor Control Lever | Adjustment | |
| Pressure at Low Idle | Pressure at High Idle (2) | |||
| Converter Inlet Pressure "P3" | (A) | - | This pressure is a maximum of 980 kPa (142 psi) with cold oil. This pressure is a maximum of 827 kPa (120 psi) with oil at normal operating temperature. |
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| Converter Outlet Pressure | (B) | - | This pressure is a minimum of 380 kPa (55 psi) and a maximum of 620 kPa (90 psi). The transmission is in THIRD gear and in FORWARD position. The torque converter is in a stall condition. |
Add spacers (28) or remove spacers (28) . (3) |
| Oil Pump | (C) | - | 2896 ± 70 kPa (420 ± 10 psi) |
Refer to "Transmission Hydraulic Control Relief Valve - Adjust". |
| Number 1 clutch | (D) | 2210 ± 70 kPa (320 ± 10 psi) |
2210 ± 70 kPa (320 ± 10 psi) |
- |
| Number 4 clutch | (E) | 2210 ± 70 kPa (320 ± 10 psi) |
2210 ± 70 kPa (320 ± 10 psi) |
- |
| Number 2 clutch | (F) | 2210 ± 70 kPa (320 ± 10 psi) |
2210 ± 70 kPa (320 ± 10 psi) |
- |
| Number 5 clutch | (G) | 1725 ± 70 kPa (250 ± 10 psi) |
1725 ± 70 kPa (250 ± 10 psi) |
- |
| Number 3 clutch | (J) | 2210 ± 70 kPa (320 ± 10 psi) |
2210 ± 70 kPa (320 ± 10 psi) |
- |
| Number 6 clutch | (K) | 2210 ± 70 kPa (320 ± 10 psi) |
2210 ± 70 kPa (320 ± 10 psi) |
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| Transmission Lubrication Oil | (L) | This pressure is a minimum of 21 kPa (3 psi). |
This pressure is 145 to 179 kPa (21 to 26 psi) at 2100 rpm. The transmission is in THIRD gear and in NEUTRAL position. |
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| ( 1 ) | This data is taken when the following conditions are met: oil at normal operating temperature, parking brake engaged and installed axle shafts. |
| ( 2 ) | The data in this column is taken with the engine at high idle. The transmission lubrication pressure is not taken with the engine at high idle. |
| ( 3 ) | Refer to Table 3. |
Pressure Tap Locations
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| Illustration 2 | g00946651 |
Converter Inlet P3 Pressure Port (A) Converter Inlet P3 | |
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| Illustration 3 | g00287162 |
Relief Valve (B) Torque converter outlet pressure tap | |
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| Illustration 4 | g00819531 |
Transmission Oil Filter (C) Pressure tap for transmission oil pump | |
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| Illustration 5 | g00873995 |
Transmission Control Valve (D) Pressure tap for the Number 1 clutch (E) Pressure tap for the Number 4 clutch (F) Pressure tap for the Number 2 clutch (G) Pressure tap for the Number 5 clutch (J) Pressure tap for the Number 3 clutch (K) Pressure tap for the Number 6 clutch | |
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| Illustration 6 | g00946665 |
Lubrication Oil Pressure Tap (L) Lubrication Oil Pressure Tap | |
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| Illustration 7 | g00819540 |
Torque Converter Outlet Relief Valve (4) Relief valve body (17) Relief valve (18) Spacers | |
| Spacers | |||
| Pressure Change for the Valve (1) | |||
| Description | Thickness | Pressure Change | Location of Spacers |
| 5M-9622 Spacer (28) | 1.60 mm (.063 inch) |
39.1 kPa (5.67 psi) |
Outlet relief valve (4) |
| 5M-9623 Spacer (28) | 0.90 mm (.035 inch) |
22.3 kPa (3.24 psi) |
|
| 5M-9624 Spacer (28) | 0.25 mm (.010 inch) |
7.6 kPa (1.10 psi) |
|
| ( 1 ) | Result of the addition of one spacer or the removal of one spacer to the valve. |
| Speed Range and Direction | Engaged Clutches and Energized Solenoids |
| Fourth Speed Forward | 3 and 2 |
| Third Speed Forward | 4 and 2 |
| Second Speed Forward | 5 and 2 |
| First Speed Forward | 6 and 2 |
| Neutral | 3 |
| First Speed Reverse | 6 and 1 |
| Second Speed Reverse | 5 and 1 |
| Third Speed Reverse | 4 and 1 |
| Fourth Speed Reverse | 3 and 1 |
Transmission Hydraulic Control Relief Valve - Adjust
Perform the following procedure in order to adjust the relief valve. The relief valve maintains the system pressure in the control section of the power train oil pump.
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| Illustration 8 | g00946634 |
Section view of the transmission hydraulic control relief valve (1) Transmission hydraulic control relief valve (19) Jam nut (20) Adjustment screw | |
- Adjust the relief valve.
- Loosen jam nut (19). Maintain the position of adjustment screw (20).
- Turn adjustment screw (20) until the desired pressure is attained.
Note: One turn of the adjustment screw causes the relief valve pressure to change by an increment of 235 kPa (34 psi).
- Do not allow adjustment screw to rotate when the jam nut is tightened.
- Tighten the jam nut to a torque of 18 ± 4 N·m (13 ± 3 lb ft).