Ford 5R55W, 5R55S, and 5R55N Transmissions
Apply oil for both the Overdrive and Intermediate servos on Ford's 5R55W, 5R55S, and 5R55N type transmissions comes up through the servo pin bore and through the hollow pin, applying the servo. This requires the pin to seal in the servo pin bore, as does the release oil used by both servos. As time goes by and the servos go through many apply and release cycles, the case wears and the pin no longer seals. This is especially true of the Overdrive servo, which is used for second gear as well as fifth. This means that the servo cycles twice every time the vehicle takes off from a stop and achieves cruising speed. This wear causes both the apply and release oil to leak, dumping pressure. With these pressure loses, the servo both lacks adequate pressure to either hold the band completely applied or release it quick enough to avoid burning it.
The 5RW kit contains all tooling necessary to repair both the overdrive and intermediate servo pin bores. It is a BLACK series kit, and is available as either a Master (pictured) or Sub kit.