A/T - 440T4 No Vehicle Movement/Any Direction

TSB: 87-40 (June)

SUBJECT: 440 T4

PROBLEM: No vehicle movement, any direction

POSSIBLE CAUSE: Cracked input sprag outer race

Before removing the transmission from the vehicle, perform all the preliminary diagnosis, such as oil pressure checks, and linkage adjustment. Several things can be responsible for a "no move" condition.




To check for a cracked race, dis-assemble the input sprag until there are no parts left in the outer race. Reach inside the outer race with both hands and pull outward. If no cracks are visible, turn the race slightly and pull again. Continue this until you have gone completely around the race.

If any cracks are present, this would allow the race to spread under load. The sprag will not hold under these conditions.

Note
An input sprag that is bad, and not holding, will give the same symptoms -- no vehicle movement.