Symptoms:

  • No lockup
  • No TCC release
  • Engine stall
  • TCC codes
  • Excess TCC slip
  • Premature TCC apply
  • Soft TCC apply
  • Harsh TCC apply

Cause:

Bore wear at the TC switch valve allows pressure loss that leads to drivability concerns.

Correction:

Recover hydraulic control and renew TCC performance by reconditioning the bore and installing Sonnax oversized TC switch valve.
  • 845RE, ZF8HP45, ZF8HP55, ZF8HP70 Oversized TC Switch Valve 35740-05
  • 845RE, ZF8HP45, ZF8HP55, ZF8HP70 Oversized TC Switch Valve 35740-05

You need this if...

Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.

845RE, ZF8HP45, ZF8HP55, ZF8HP70 Oversized TC Switch Valve Vacuum Test Locations