• Soft slide shifts
  • Delayed Reverse
  • Low line rise
  • Direct clutch failure


Severe wear of the pressure regulator boost sleeve allows boost oil leakage.


The Sonnax drop-in boost valve kit includes a highly wear-resistant aluminum sleeve to restore hydraulic integrity.


Boost Valve Kit
Part No. 76990-03K

Factory style sleeve, no O-rings

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

Vehicles with Ford AOD transmissions frequently have problems with poor line rise, which results indirect clutch failures and soft shift slides. These complaints are often caused by severe wear of the boost sleeve, allowing oil leakage. The hardened steel boost valve continuously reciprocates within the aluminum boost sleeve, and wears the inside diameter of the sleeve. This excessive leakage can be eliminated by installing the drop-in Sonnax boost valve kit 76990-03K.

  • Highly wear-resistant aluminum sleeve prevents wear
  • Steel valve has been tightly toleranced to allow minimum clearance with the inside diameter of the sleeve
  • Kit restores the hydraulic integrity of the assembly
  • Drop-in Zip Valve™ parts install quickly and easily
Boost Valve Ratios
Part Numbers Ratios Great for these Applications
76990K & 76990-03K .545" Spool Standard Ratio Standard OE
76990-04K .553" Spool Large Ratio Large Ratio OE & High Performance

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 AOD Valve Body Layout

Ford AOD Valve Body Layout
  • AOD Boost Valve Kit 76990-03K
  • AOD Boost Valve Kit 76990-03K

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.

AOD Boost Valve Kit Vacuum Test Locations