November 14, 2016
The oversized reverse boost valve and sleeve supplied in these kits must be used when replacing the PR valve.
Common complaints in vehicles with listed Ford transmissions is low line pressure resulting or band and/or clutch failure, or throttle-sensitive buzz, especially when hot. These issues can be caused by severe wear at the outboard pressure regulator valve spool or bore area. Wear at this location allows EPC oil to leak to exhaust, resulting in poor line rise. As oil temperature increases it becomes less viscous, an more leakage occurs. Wear at the inboard balance spool bore is also very common, which can result in excessively high line pressure that can damage the case. Sonnax oversized pressure regulator and boost valve kit 76948-17K restores valve-to-bore clearances so the pressure regulator valve can maintain correct pressures.
There are two reaming options available for this kit. Either tool kit works for all model years.
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.