Symptoms:

  • Poor shift quality
  • Low line pressure
  • Flare shifts
  • High line pressure
  • Harsh shifts
  • Burnt converter
  • Delayed Reverse
  • No Reverse
  • TCC slip

Cause:

Pressure regulator bore wear allows fluid loss that causes erratic line pressure and poor drivability.

Correction:

Recover pressure control and renew shift quality by reconditioning the bore and installing Sonnax oversized pressure regulator valve kit.

ZF6HP21, ZF6HP28, ZF6HP34

Oversized Pressure Regulator Valve Kit
Part No. 95740-69K

ZF valve name: SYS.DR-V


You need this if... View Instructions Find a Distributor

In ZF6HP21/28/34 (Gen. 2) valve bodies, wear is commonly found at different areas in the pressure regulator bore. Wear at the balance end causes high pressure spikes leading to broken drums, pistons or other parts and wear at the spring end of the bore allows low line pressure and lube/TC fluid to exhaust, leading to burnt converter clutches and premature bushing failure. The Sonnax oversized pressure regulator valve kit 95740-69K restores valve-to-bore clearances to maintain correct pressures.

  • Valve is hardcoat anodized to resist wear
  • Sleeve is made from highly wear-resistant aluminum

Kit is NOT compatible with ZF6HP19/26/32 (Gen.1) units. To differentiate between Gen. 1 and Gen. 2 valve bodies, see ZF Identification Guide.

  • Valve
  • Sleeve

Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.

ZF6HP21/28/34 (Gen. 2) Valve Body Layout

ZF6HP21/28/34 (Gen. 2) Valve Body Layout
  • ZF6HP21, ZF6HP28, ZF6HP34 Oversized Pressure Regulator Valve Kit 95740-69K

You need this if...

Vacuum tests at the ports indicated fail to hold the recommended minimum of in-Hg.

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