845RE/ZF8HP45/8HP55/8HP70 Sonnax Zip Kit Valve Body Repair

This is the Sonnax ZF8-ZIP Zip Kit, the drop-in valve body repair for the ZF 8HP45, 8HP55 and 8HP70 eight-speeds and their Chrysler 845RE cousin. You will find these transmissions under Ram 1500, Jeep Grand Cherokee and Wrangler, Dodge Durango and Chrysler 300, along with a long list of BMW, Audi, Jaguar and Land Rover applications. When the aluminum valve body bores wear, apply pressure bleeds off and you get the classic complaints: harsh or delayed engagement, slipping under load, flare on the 4-5 and 5-6 shifts, and codes for clutch pressure.

The kit reseals the critical clutch-apply and accumulator circuits with precision-machined Zip Valve parts that install without reaming or special tools. Each part is sized to restore the pressure the worn bore lost, so you cure the root cause instead of chasing symptoms. A detailed technical booklet ships in the box with circuit-by-circuit inspection and rebuild notes.

Fitment matters here: this ZF8-ZIP kit covers ZF8HP45, ZF8HP55, ZF8HP70 and 845RE valve bodies only. If you are working on a ZF8HP50, ZF8HP75 or 850RE (the Gen 2 castings), you need the separate ZF8-GEN2-ZIP kit instead. Verify your valve body against the Sonnax identification guide before ordering.