Sonnax and Transtar highlight the case saver kit for Ford 6F35 transmissions.
According to the companies, first- and second- generation 6F35 transmissions are notorious for worn axle bushings, which allow external leakage. This premature bushing wear can be caused by a worn differential support, which affects endplay negatively. The thrust bearing that rides on the differential support rotates, wearing deeply into the aluminum support and allowing endplay to become excessive. To correct endplay, a new case half is required.

This case from Sonnax is built to restore endplay to proper levels, the company says. According to the companies, non-rotating shims correct differential endplay, prevent future wear and prevent repeat bushing failure caused by excess endplay.
Car models covered are as follows:
