Chrysler 68RFE transmissions commonly exhibit wear in the low/reverse bore. This issue stems from the valve getting side-loaded due to the length of the valve being dimensionally close to its diameter. As wear progresses, hydraulic fluid cross leaks to other circuits and results in the loss of apply pressure to the low/reverse clutch. This leads to burnt low/reverse clutch, delayed/no Reverse, and no engine breaking when in Low.
Reconditioning the bore and installing Sonnax oversized low/reverse switch checkball sleeve kit 92835-45K restores hydraulic integrity to re-establish normal shift operation and prevents premature wear.
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.