A/T - Rear Planet Failure/Lack Of Lubrication

TSB 89-16 (June)

SUBJECT: FORD

PROBLEM: Rear planet failure, due to lack of lubrication

CAUSES: There can be several causes:

1. Cooler restrictions, or crimped auxiliary cooler hoses (SIL 86-8).

2. Direct shaft worn into drum, and rubbing the output shaft (TSB 88-40).




3. Cooler checkball in pump cover is restricted. (See figure) Debris from the converter flows through the passage and can lodge next to the ball, which severely restricts lube flow around the ball. The planets need all of the lube flow available, and the pinion shafts and bearings will "blue" and/or seize if any lube flow is lost.

SOLUTIONS:
Always be sure to clean the check ball thoroughly.

Many rebuilders are removing the spring in this passage to improve cooler flow. This seems to be working quite effectively.