Troubleshooting Guide

TROUBLESHOOTING GUIDE

The following information has been provided to aid in identifying the cause of a problem when examining a malfunctioning transmission. It is necessary to consider the torque converter charging pump, transmission, oil cooler and all connecting lines as a complete unit when determining the source of the problem since the condition and proper operation of all of these components effects the performance. By referring to how the unit operates together with this information service personnel should be able to correct any malfunction that may occur with the transmission.

The troubleshooting procedure consists of two classifications: Mechanical and Hydraulic.

Mechanical Checks

Before examining the transmission from a hydraulic point of view, the following mechanical checks should be made:

1. Check all control linkages are properly connected and adjusted at all connecting points. 2. Check all transmission control levers and cables for bindings and restrictions in travel that would prevent full engagement. Shift the transmission control levers by hand at the control valve, if full engagement cannot be obtained the cause may be in the control cover and valve assembly. 3. Check the input shaft is rotating when the engine is running.

Hydraulic Checks

Before checking the torque converter, transmission or associated hydraulic system for pressures and rate of oil flow, it is essential that the transmission oil level is checked first.

Cause Remedy

1. Low oil level 1. Fill to correct level

2. Clutch pressure regulating valve stuck open 2. Clean valve spool and housing or replace

3. Faulty charging pump 3, Replace pump

4. Broken or worn clutch shaft or piston sealing rings 4. Replace sealing rings

5. Clutch piston bleed valve stuck open 5. Remove piston and clean bleed valves

Low Converter Charging Pump Output

Cause Remedy

1. Low Oil level 1. Fill to correct level

2. Suction screen blocked

3. Defective oil pump 2. Clean suction screen

3. Replace pump

Overheating

Cause Remedy

1. Worn oil sealing rings 1. Remove, Disassemble and rebuild converter assembly 2. Defective oil pump 2. Replace pump

3. Low oil level 3. Fill to correct level

4. Excessive load 4. Ensure machines are not overloaded

Noisy Converter

Cause Remedy

1. Worn coupling gears 1. Replace

2. Worn oil pump 2. Replace pump

3. Worn or damaged bearings 3. Remove, disassemble and rebuild converter

Lack of Power

Cause Remedy

1. Low engine RPM at converter stall 1. Check engine governor and injectors

2. High engine RPM at converter stall 2. Check clutch pressure and pump output

3. See ‘Overheating’ and make the same checks 3. Remove, disassemble and rebuild converter