1988 to 2007 Dodge, Ram and Jeep vehicles fitted with the small case transmissions such as the A500, 40RH, 42RH, 40RE, 42RE, 44RE or with the big case transmission such as the A518, 46RH, 46RE, A618, 47RH, 47RE and 48RE automatic transmission often wear out the boost valve bore. The boost valve bore wears out in the area of the large land. The large land is the reaction area for the throttle pressure. The throttle pressure acts on the boost valve, which in turn acts on the pressure regulator valve to raise the main line pressure accordingly. This is the main reason for the common reverse band burn up.
Adequate main line pressure rise is required to provide enough clamping force under all load conditions to prevent slipping, as well as to achieve proper shift quality. Consequently, a compromised boost valve will cause complaints of soft shifts and burnt frictions and TCC slip.
Features and benefits:
The TransGo drop-in USA-made hardened steel boost valve and boost plug provides you with a durable direct replacement for the OEM assembly. The boost valve has a re-positioned longer land, as a result this new valve is a fix even with substantial bore wear. This assembly is a direct drop-in replacement for both the early two-pieces and the late one-piece valve.
Corrects/Prevents/Reduces:
Burnt reverse band
Soft shifts as well as burnt friction elements
Lazy or erratic pressure rise
TCC slip
Includes:
USA-made hardened boost valve
USA-made hardened boost plug
Boost valve tapered spring
TransGo Technical Support
If you are having trouble choosing the correct TransGo part, or have questions before, during or after installation of this part, TransGo's ASE Certified Technicians are available to help.
TransGo Technical Support