Symptoms:

  • Delayed engagement
  • Flare shifts
  • Harsh downshifts
  • Neutral shifts
  • High line pressure
  • Harsh upshifts
  • Wrong gear starts
  • Gear ratio & solenoid codes
  • TCC slip

Cause:

All solenoids are fed by the solenoid regulator valve. Worn valve/bore surfaces allow critical pressurized oil to cross-leak to the sump, reducing available oil pressure and volume for the solenoids. Shift quality will be adversely affected by wear and operating temperatures.

Correction:

Sonnax oversized solenoid pressure regulator valve kit eliminates cross-leaks and loss of critical oil to the sump, restoring correct oil pressure and volume available to the solenoids.
  • ZF6HP21, ZF6HP28, ZF6HP34 Oversized Solenoid Pressure Regulator Valve Kit 95740-64K
  • ZF6HP21, ZF6HP28, ZF6HP34 Oversized Solenoid Pressure Regulator Valve Kit 95740-64K

You need this if...

ZF6HP21, ZF6HP28, ZF6HP34 Oversized Solenoid Pressure Regulator Valve Kit Vacuum Test Locations