There are two styles of the OE Reverse servo piston plug in Chrysler RWD units:
The extended tip version for the 47RH/RE (A618) and 48RE
The flat tip version for the 40RH, 42RH/RE, 44RE (A500), 46RH/RE (A518), 36RH, 37RH (A727) and 30RH (A904).
Both versions of these OE aluminum plugs are subject to wear, galling and breaking at the spring seat area due to high stresses in Reverse. Sonnax steel reverse servo piston plug kit 22912-01K won't break or wear like the OE plug and can be configured to work in both styles of RWD units.
Hardened steel for more than twice the strength of OE plugs
Exclusive, leak-free design uses O-ring between plug and piston
Universal replacement for both extended and flat-tip plug styles