Troubleshooting the automatic transmission is simplified by using the proven method of diagnosis. One of the most important things to remember is that there is a definite procedure to follow. Do not take short cuts or assume that critical checks or adjustments have already been made.

The following procedures are recommended for checking and/or verifying that the various components are adjusted and operating properly. Use Rotunda Automatic Transmission Tester 014-00737 or equivalent. Follow the manufacturer's instructions.

Transmission Fluid Condition Check

1. Make the normal fluid level check as outlined.

2. Observe color and odor of the fluid. It should be dark reddish, not brown or black. Odor can sometimes indicate that there is an overheating condition or clutch disc or band failure.

3. Use an absorbent white facial tissue to wipe the dipstick. Examine the stain for evidence of solids (specks of any kind) and for antifreeze signs (gum or varnish on dipstick).

   If specks are present in the oil or there is evidence of antifreeze, the transmission oil pan must be removed for further inspection. If fluid contamination or transmission failure is confirmed by further evidence of coolant or excessive solids in the oil pan, the transmission must be disassembled and completely cleaned and serviced. This includes cleaning the torque converter and transmission cooling system. It would be a waste of time to perform any further checks before cleaning and servicing the transmission. During disassembly and assembly, all overhaul checks and adjustments of clearances and end play must be made. After the transmission has been serviced, all diagnosis tests and adjustments listed in the Diagnosis chart must be completed to ensure the concern has been corrected.

High or Low Fluid Level

A fluid level that is too high will cause the fluid to become aerated (foamy). Aerated fluid will cause low control pressure and the aerated fluid may be forced out the vent.

A fluid level that is too low can affect the operation of the transmission. Low level may indicate fluid leaks that could cause transmission damage.

Fluid Level High Before Starting Engine, OK During Normal Check

1. Check for correct operation of drainback valve in stator support.

2. Check pump bushing.

3. Replace or service pump, if required.