Symptoms:

  • Delayed engagement
  • Wrong gear starts
  • Flare shifts
  • Gear ratio & solenoid codes
  • Harsh shifts
  • Neutral shifts
  • Gear loss

Cause:

Bore wear at the priming valve allows pressure escape that causes drivability problems.

Correction:

Stop pressure loss and restore normal solenoid feed pressures by reconditioning the bore and installing Sonnax oversized priming valve kit. 
  • 845RE, ZF8HP45, ZF8HP55, ZF8HP70 Oversized Priming Valve Kit 35740-21K
  • 845RE, ZF8HP45, ZF8HP55, ZF8HP70 Oversized Priming Valve Kit 35740-21K

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 Priming Valve Kit Vacuum Test Locations