The AS66RC (gas) and AS69RC (diesel) secondary pressure regulator plunger valves are different diameters and should not be interchanged, as different converter charge pressures will result. Measure the plunger valve and/or reference sleeve slot to determine proper replacement kit.
A worn secondary pressure regulator plunger valve sleeve in AS69RC transmissions can cause reduced SLT pressure, TCC codes and shudder, and overheating. The plunger valve is reacted on by SLT pressure, which allows throttle control of the converter charge circuit. As the OE sleeve wears, SLT pressure exhausts, compromising the converter charge circuit and resulting in the noted symptoms. Sonnax secondary pressure regulator plunger valve kit 122740-05K restores the hydraulic control, and fixes these issues.
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.