Jeep Cherokee

 Service Manual

Transmission and transfer case » AW-4 automatic transmission » Diagnosis and testing
Causes of burnt fluid

Burnt, discolored fluid is a result of overheating which has two primary causes.

(1) A result of restricted fluid flow through the main and/or auxiliary cooler. This condition is usually the result of a faulty or improperly installed drainback valve, a damaged main cooler, or severe restrictions in the coolers and lines caused by debris or kinked lines.

(2) Heavy duty operation with a vehicle not properly equipped for this type of operation. Trailer towing or similar high load operation will overheat the transmission fluid if the vehicle is improperly equipped. Such vehicles should have an auxiliary transmission fluid cooler, a heavy duty cooling system, and the engine/axle ratio combination needed to handle heavy loads.

General diagnosis information

Effects of incorrect fluid level

Causes of burnt fluid

Fluid contamination

Preliminary inspection and adjustment

Manual shifting test

Hydraulic pressure test

Pressure test analysis

Time lag test

Test procedure

Time lag test analysis

Service diagnosis

Transmission solenoid testing

Park/neutral position switch

Gearshift cable

Throttle valve cable

Speed sensor testing

Flow testing transmission main cooler

Torque converter stator clutch inspection