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


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


Sonnax drop-in boost valve kit is made from special aluminum to prevent wear.


Boost Valve Kit
Part No. 76990-04K

Large Ratio, Factory-Style Sleeve, No O-Rings

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

When rebuilding high performance or heavy-duty Ford AOD units, many rebuilders wish to increase line rise over the OE specifications. This is now easily accomplished by installing Sonnax large ratio boost valve kit 76990-04K. Not only will our sleeve and valve kit address poor line rise, direct clutch failure and soft slide shift complaints due to the OE sleeve being worn, but is now available in a larger boost ratio.

  • Large ratio boost sleeve is made from a highly wear-resistant aluminum and comes without O-rings for ease of installation
  • Steel valve has been tightly toleranced for minimal leakage and extended life
  • 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

For standard OE ratio replacements, order 76990K with O-rings or 76990-03K with factory-style sleeve.

  • 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 76990-04K
  • AOD Boost Valve Kit 76990-04K

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