It is often difficult to reduce the total transmission endplay in listed Chrysler units. Excessive total and/or rear unit endplay is often the result of gear, snap ring and/or spline wear. Rear unit endplay is often difficult to reduce with available selective washers. When rear unit endplay is loose, the total unit endplay measurement is also excessive. Sonnax offers .010" rear planet endplay shim 12780-Z, which is installed between the #9 thrust washer and the rear planetary.

• Adding a shim or shims between the OE thrust washer and the rear planetary reduces rear unit endplay, which also reduces total assembled transmission endplay.
• This shim will fit either the 3- or 4-tanged OE thrust washer design.