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 pressure regulator 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 excess leakage can be eliminated by installing Sonnax boost valve kit 76990K.
|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|
O-Ring seals are added insurance against boost oil loss. Sleeve can be installed without these seals, but their use is recommended