Symptoms:

  • Overheating
  • Overheated fluid

Cause:

The thermal bypass valve in the OE cooler bypass valve can become stuck in the cooler bypass position, causing hot fluid to circulate in the transmission that leads to overheating.

Correction:

Removing the OE thermal bypass valve and replacing with the Sonnax thermal bypass eliminator ensures fluid always circulates through the cooler and keeps temps down.

45RFE, 545RFE, 65RFE, 66RFE, 68RFE, 845RE, AS69RC, ZF8HP45, ZF8HP70

Thermal Bypass Eliminator Kit
Part No. 72760-01K

For use in OE part numbers 52014762AA, 68186711AB, 68291739AA and 68210018AA.

View Instructions Find a Distributor

The OE thermal bypass valve in listed units is known to get stuck in recirculation mode, only allowing fluid to circulate in the transmission and not allowing flow through the cooler. Sonnax thermal bypass eliminator kit 72760-01K allows reuse of the OE cooler block with the built-in pressure relief by removing the old OE thermal bypass valve and replacing it with a plug that permanently allows flow through the cooler.

  • Drop-in Zip Valve™ parts install quickly and easily into OE cooler bypass valve
  • Less expensive than replacing the OE cooler bypass valve

Learn More About Zip Valve™ Drop-In Repairs
  • Plug
  • O-Ring

  • 45RFE, 545RFE, 65RFE, 66RFE, 68RFE, 845RE, AS69RC, ZF8HP45, ZF8HP70 Thermal Bypass Eliminator Kit 72760-01K
  • 45RFE, 545RFE, 65RFE, 66RFE, 68RFE, 845RE, AS69RC, ZF8HP45, ZF8HP70 Thermal Bypass Eliminator Kit 72760-01K