Wear at the pressure regulator valve bore and reverse boost sleeve allows valuable EPC, line pressure and reverse boost to exhaust.
The Sonnax kit includes an oversized pressure regulator valve to restore correct clearances for proper hydraulic control, and a replacement reverse boost valve assembly.
The oversized reverse boost valve and sleeve supplied in these kits must be used when replacing the PR valve.
Common complaints in vehicles with AODE and 4R70W 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 lie pressure that can damage the case. The Sonnax oversized pressure regulator valve and matching boost valve kit 76948-16K 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.
November 14, 2016
Topics: Vacuum Test Guides Vacuum Testing Transmission Ford 4R75W Transmission 4R70W Transmission AODE Transmission 4R70E Transmission 4R75E TransmissionRead Now
Contact a Sonnax Parts Distributor.
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected