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Fitment Type: Performance/Custom

Items Included: High-Ratio Boost Valve and Sleeve

Manufacturer Part Number: 76990-04K

Material: Aluminum

Vintage Part: No

Brand: Sonnax

Transmission Model: AOD

Type: Valve Body

Interchange Part Number: SNX-76990-04K

Year Range: 1980-1993

Universal Fitment: Yes

Transmission Make: Ford, Lincoln, Mercury

Performance Part: Yes

AOD Transmission Valve Body

Boost Valve Kit
Part No. 76990-04K

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

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

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

  • Valve
  • Sleeve

Symptoms:

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

Cause:

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

Correction:

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

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