Symptoms:

  • Low Reverse boost
  • Delayed Reverse
  • Reverse slip
  • No Reverse
  • Low line rise in Reverse
  • Burnt Reverse clutch

Cause:

Worn OE boost sleeve allows critical pressure loss that prevents proper Reverse operation.

Correction:

Stop boost leakage and renew Reverse performance by installing Sonnax drop-in boost valve kit.

4R70E, 4R70W, 4R75E, 4R75W, AODE

Boost Valve Kit
Part No. 76948-02K

Fits '91-later units.

You need this if... View Instructions Find a Distributor

Ford vehicles with 4R70E, 4R70W, 4R75E, 4R75W and AODE transmissions may exhibit insufficient line rise in Reverse, delayed or slipping Reverse, and/or a burnt Reverse clutch. Continuous oscillation of the OE boost valve within the boost sleeve causes premature wear, creating a path for boost pressure to exhaust and causing these concerns. Installing Sonnax boost valve kit 76948-02K eliminates pressure loss, restoring proper line rise and robust Reverse action.

  • Hardcoat anodized aluminum valve combats premature wear
  • Sleeve manufactured from highly wear-resistant aluminum
  • Drop-in Zip Valve™ parts install quickly and easily
Learn More About Zip Valve™ Drop-In Repairs
  • Valve
  • Sleeve

Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.

Ford AODE, 4R70W, 4R75W, 4R70E, 4R75E Valve Body Layout

Ford AODE, 4R70W, 4R75W, 4R70E, 4R75E Valve Body Layout
  • 4R70E, 4R70W, 4R75E, 4R75W, AODE Boost Valve Kit 76948-02K
  • 4R70E, 4R70W, 4R75E, 4R75W, AODE Boost Valve Kit 76948-02K

You need this if...

Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.

4R70E, 4R70W, 4R75E, 4R75W, AODE Boost Valve Kit Vacuum Test Locations