Troubleshooting - (Power Shift)

Use this as a reference for the location and correction of problems in the power train. When more checks are necessary, use the 5P6225 Transmission Hydraulic Test Group. Locations of the pressure taps and procedures for testing and adjusting are given in the D4E POWER SHIFT TRANSMISSION TESTING AND ADJUSTING, Form No. SENR7632.

Always make visual checks first. Then check the operation of the machine and go on to check with the instruments.

Visual Checks

1. Check the oil levels of the transmission and the steering clutch and bevel gear case.

2. Check the oil level in the final drives.

3. Check all oil lines, hoses and connections for leaks and damage. Look for oil on the ground under the machine.

4. Check the control linkages for the transmission, steering clutches and brakes for damage and/or adjustment.

5. Check the adjustment of the track.

6. Let the oil out of the filter housing. Remove and check the filter element for foreign materials. Check the screen in the bottom of the transmission housing.

a. Bronze-colored particles give an indication of a clutch failure.

b. Shiny steel particles give the indication of a pump failure.

c. Rubber particles give an indication of a seal or hose failure.

d. Aluminum particles give an indication of a torque converter failure.

If you find metal or rubber particles, all components of the transmission hydraulic system must be washed clean. Do not use parts with damage. Use new parts.

Checks During Operation

With the engine running, move the transmission selection lever to all speed positions. The detents must be felt in all positions.

Operate the machine in each direction and in all speeds. Make note of all noises that are not normal and find their sources. If the operation is not correct, make reference to the CHECK LIST DURING OPERATION for "problems" and "probable causes."

Check List During Operation

Transmission

Problem: Transmission Does Not Operate In Any Speed Or Does Not Engage (Slips) In All Speeds.

PROBABLE CAUSE:

1. Low oil pressure caused by:

a. Low oil level.

b. Control linkage loose or adjustment not correct.

c. Failure of the oil pump or the pump drive.

d. Air leaks on inlet side of pump.

e. Differential valve not moving.

f. Leakage inside the transmission.

g. Adjustment of the pressure relief valve not correct, or valve does not close.

h. Load piston or pressure differential valve not moving.

2. Mechanical failure in transmission.

3. Failure of torque converter.

4. Bevel pinion and/or bevel gear failure.

5. Failure in steering clutches.

6. Failure in final drives.

Problem: Transmission Does Not Make A Shift.

PROBABLE CAUSE:

1. Control linkage loose or adjustment not correct.

2. Low oil level.

3. Low clutch pressures.

Problem: Slow Shifts.

PROBABLE CAUSE:

1. Low oil pressure.

2. Adjustment of control linkage not correct.

3. Air leaks on inlet side of pump.

4. Load piston or pressure differential valve not moving.

Problem: Transmission Engages Very Suddenly (Rough Shifts).

PROBABLE CAUSE:

1. Initial setting of the pressure modulating valve not correct.

2. Adjustment of control linkage not correct.

3. Load piston or pressure differential valve does not move.

4. Valve springs that are weak or have damage.

Problem: Transmission Operates In Forward Speeds Only.

PROBABLE CAUSE:

1. Control linkage loose or adjustment not correct.

2. No. 1 clutch not engaged (slips) because of:

a. Low oil pressure.

b. Discs and plates have too much wear.

c. Clutch has broken parts.

Problem: Transmission Operates In Reverse Speeds Only.

PROBABLE CAUSE:

1. Control linkage loose or adjustment not correct.

2. No. 2 clutch not engaged (slips) because of:

a. Low oil pressure.

b. Discs and plates have too much wear.

c. Clutch has broken parts.

Problem: Transmission Does Not Operate In First Speed Forward Or Reverse.

PROBABLE CAUSE:

1. No. 5 clutch not engaged (slips) because of:

a. Low oil pressure.

b. Discs and plates have too much wear.

c. Clutch has broken parts.

Problem: Transmission Does Not Operate In Second Speed Forward Or Reverse.

PROBABLE CAUSE:

1. No. 4 clutch not engaged (slips) because of:

a. Low oil pressure.

b. Discs and plates have too much wear.

c. Clutch has broken parts.

Problem: Transmission Does Not Operate In Third Speed Forward Or Reverse.

PROBABLE CAUSE:

1. No. 3 clutch not engaged (slips) because of:

a. Low oil pressure.

b. Discs and plates have too much wear.

c. Clutch has broken parts.

Problem: Transmission Is In A Speed When The Selection Lever Is In Neutral.

PROBABLE CAUSE:

1. Control linkage loose or adjustment not correct.

2. Direction clutch is engaged and does not release.

Problem: Transmission Engages But The Machine Does Not Move And The Engine Stops.

PROBABLE CAUSE:

1. Failure in final drives.

2. Failure in steering clutches.

3. Failure in bevel gear and pinion.

4. Gears in the transmission will not move because of:

a. Too many clutches are engaged.

b. Mechanical failure in transmission.

5. Mechanical failure in torque converter.

Problem: Transmission Gets Hot.

PROBABLE CAUSE:

1. Low oil level.

2. High oil level.

3. Core of oil cooler not completely open.

4. Low oil flow as a result of pump wear.

5. Long periods of operation with converter at or near stall speed.

6. Too much resistance between the plates and discs of the clutches when not engaged.

Problem: Pump Noise Not Normal.

PROBABLE CAUSE:

1. Loud sounds at short intervals that give an indication that particles are going through the pump are caused by pump cavitation.

2. A constant loud noise is an indication of pump failure.

3. Air at the inlet side of the pump (aeration).

Torque Converter

Problem: Torque Converter Gets Hot.

PROBABLE CAUSE:

1. Bad temperature gauge.

2. Mechanical failure in torque converter.

3. Core of oil cooler not completely open.

4. Long periods of operation with converter at or near stall speed.

5. Too much oil leakage in torque converter.

6. Too much restriction in oil cooler lines.

7. Not enough oil to torque converter because of:

a. Oil pump failure.

b. Too much oil leakage in transmission.

c. Inlet relief valve not operating correctly.

Steering

Problem: Machine Will Not Turn In One Direction.

PROBABLE CAUSE:

1. Adjustment of steering control linkage not correct.

2. Too much leakage in steering clutch control valve.

3. Steering clutch discs or plates have wear or damage.

4. Seals or steering clutch piston have damage.

Problem: Machine Will Not Turn In Either Direction.

PROBABLE CAUSE:

1. Low oil pressure to steering clutch control valve.

2. Leaks in relief valve or control valve.

3. Adjustments of control linkages for the steering clutches and brakes not correct.

4. Steering clutch or clutches not releasing.

Problem: Machine Moves In Either Direction When Both Steering Clutches Are Engaged.

PROBABLE CAUSE:

1. Adjustments of the control linkages for the steering clutches and brakes not correct.

2. Steering clutch discs or plates have wear or damage.

3. Steering clutch springs that are weak or have damage.

4. Studs that hold the steering clutch springs are broken.

5. Splines on the steering clutch hubs have damage.

Problem: Slow Steering.

PROBABLE CAUSE:

1. Control linkages for the steering clutches and brake loose or adjustment not correct.

2. Brake linings have wear or damage.

3. Low oil pressure to steering clutch control valve.

4. Splines on steering clutch hubs have damage.

5. Leaks in steering clutch control valve.

Troubleshooting - (Direct Drive)

Use this as a reference for the location and correction of problems in the power train. When more checks are necessary, use the 5P6225 Transmission Hydraulic Test Group. Use 5P5224 Pressure Gauge Kit to check steering pressure.

Always make visual checks first. Then check the operation of the machine and go on to check with the instruments.

Visual Checks

1. Check the oil levels of the flywheel clutch, transmission and bevel gear case.

2. Check the oil levels of the final drives.

3. Check all oil lines, hoses and connections for leaks or damage. Look for oil on the ground under the machine.

4. Check the control linkages for the flywheel clutch, transmission, steering clutches and brakes for damage and/or adjustment.

5. With the flywheel clutch not engaged, turn the universal joint by hand. It must turn freely. If the oil is cold, the universal joint will be harder to turn. If the universal joint does not turn, disconnect it from the flywheel clutch. Turn the universal joint again and see if the gears in the transmission turn.

6. Check the magnetic screen, oil filter and screen in engine flywheel housing for foreign materials.

If you find metal or rubber particles, all components of the transmission hydraulic system must be washed clean. Do not use parts with damage. Use new parts.

Checks During Operation

With the engine running, move the control levers for the transmission to all speed positions and the control lever for the flywheel clutch to all positions.

Operate the machine in each direction and in all speeds. Make note of all noises that are not normal and find their sources. If the operation is not correct, make reference to the CHECK LIST DURING OPERATION for "problems" and "probable cause."

Check List During Operation

Transmission

Problem: Transmission Does Not Operate In Any Speed Or Is Not Engaged (Slips) In All Speeds.

PROBABLE CAUSE:

1. Failure in flywheel clutch.

2. Mechanical failure in transmission.

3. Failure of bevel gear.

4. Failure in steering clutches.

Problem: Transmission Operates In Reverse Speeds Only Or Forward Speeds Only.

PROBABLE CAUSE:

1. Control linkage loose or adjustment not correct.

2. Mechanical failure in transmission.

Problem: Transmission Does Not Make A Shift.

PROBABLE CAUSE:

1. Control linkage loose or adjustment not correct.

2. Mechanical failure in transmission.

Problem: Transmission Does Not Remain In A Speed When Under Load Conditions.

PROBABLE CAUSE:

1. Interlock linkage adjustment not correct.

2. Interlock linkage has damage.

3. Interlock linkage spring is broken.

4. Ends of interlock plungers and/or notches in shift shafts have wear.

5. Interlock springs are weak or have damage.

Problem: Shifts Of The Transmission Are Not Easy.

PROBABLE CAUSE:

1. Shift forks have damage or wear.

Problem: Gears In The Transmission Do Not Turn.

PROBABLE CAUSE:

1. Failure of the bearings on one or more of the shafts.

2. Gear in transmission is broken.

3. One or more of the gears not correctly engaged (transmission in two speeds at the same time).

Problem: Transmission Is In A Speed When The Control Lever Is In Neutral.

PROBABLE CAUSE:

1. Control linkage loose or adjustment not correct.

2. Mechanical failure in transmission.

Problem: Transmission Gets Hot.

PROBABLE CAUSE:

1. High oil level.

Problem: Pump Noise Not Normal.

PROBABLE CAUSE:

1. Loud sounds at short intervals that give an indication that particles are going through the pump are caused by pump cavitation.

2. A constant loud noise is an indication of pump failure.

3. Air at the inlet side of the pump (aeration).

Steering

Problem: Machine Will Not Turn In One Direction.

PROBABLE CAUSE:

1. Adjustment of steering control linkage not correct.

2. Too much leakage in steering clutch control valve.

3. Steering clutch discs or plates have wear or damage.

4. Seals or steering clutch piston have damage.

Problem: Machine Will Not Turn In Either Direction.

PROBABLE CAUSE:

1. Low oil pressure to steering clutch control valve.

2. Leaks in relief valve or control valve.

3. Adjustments of control linkages for the steering clutches and brakes not correct.

4. Steering clutch or clutches not releasing.

Problem: Machine Moves In Either Direction When Both Steering Clutches Are Engaged.

PROBABLE CAUSE:

1. Adjustments of the control linkages for the steering clutches and brakes not correct.

2. Steering clutch discs or plates have wear or damage.

3. Steering clutch springs that are weak or have damage.

4. Studs that hold the steering clutch springs are broken.

5. Splines on the steering clutch hubs have damage.

Problem: Slow Steering.

PROBABLE CAUSE:

1. Control linkages for the steering clutches and brakes loose or adjustment not correct.

2. Brake linings have wear or damage.

3. Low oil pressure to steering clutch control valve.

4. Splines on steering clutch hubs have damage.

5. Leaks in steering clutch control valve.