Symptoms:

  • Inconsistent shift quality

Cause:

Valves, springs and pressurized fluid repeatedly push on the end plugs, causing the plugs to deform and wear. As a result, critical pressure is lost due to excessive clearance between the plug and bore.

Correction:

The Sonnax O-ringed end plugs restore correct circuit pressures. The O-ring provides additional sealing to reduce pressure losses past the end plug.

ZF6HP21, ZF6HP28, ZF6HP34

O-Ringed End Plug Kit
Part No. 95740-27K

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

Valves, springs and pressurized fluid repeatedly push on end plugs causing them to deform and wear. As a result, critical pressure is lost due to excessive clearance betweeen the plug and bore. Sonnax O-ringed end plug kit 95740-27K services the eight individual bores in the ZF6HP21/28/34 (Gen. 2) valve body which use internal end plugs to isolate valves from solenoids. The O-ringed end plugs replace damaged OE end plugs and restore pressure containment to the valve bore.

Also available for this unit is the double O-ringed end plug kit 95740-30K that services all seven of the 12mm dia. bores.

  • Prevents loss of critical pressure
  • Requires no machining or special tools
  • Services all seven bores to isolate valve from solenoids with 12mm internal end plugs
ID Valve Location Dia.
Upper Valve Body
A Clutch D1 Brake Regulator 13mm
B M-Shift = Shift Valve 3
E-Shift = Position Valve
13mm
Lower Valve Body
C Clutch A Control Pressure Regulator 15mm
D Clutch E Control Pressure Regulator 15mm
E Clutch Cooling 13mm
F Bypass Clutch Control Regulator 13mm
G Converter Release Regulator 13mm
H Lubrication Control 13mm

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.

  • Large End Plugs (2) 15mm Dia.
  • Large O-Rings (4) 2 extra
  • Small End Plugs (6) 13mm Dia.
  • Small O-Rings (9) 3 extra

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 O-Ringed End Plug Kit 95740-27K

You need this if...

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

Note: Port configurations may change due to variations of casting channels between M and E shift, as well as make and model. The location that needs checking will be the first port inboard of the end plug.

ZF6HP21, ZF6HP28, ZF6HP34 O-Ringed End Plug Kit Vacuum Test Locations