One limitation of the R-series transmission is it’s first gear thrust washer. The factory thrust washer fails under heavy loading due to a narrow cross-section with a square lock-pin keyway. Marlin Crawler has developed a new thrust washer that features a larger cross-section with a rounded lock-pin keyway. To top it off, it’s made from heat treated Chromoly steel. New hardened pin included.
Applications include R150, R150F, R151, R151F, R154, and other R-series transmissions.