Symptoms:

  • 1-2 Flare
  • Delayed engagement
  • Low Reverse pressure
  • 1-2 Band burned

Cause:

Continuous reciprocation of the 1-2 (Forward) and Reverse servo boost valves wearing the valve body bores.

Correction:

Sonnax oversized 1-2 and Reverse servo boost valve kit restores hydraulic integrity, and has increased valve-to-bore contact to prevent leakage.

4T60, 4T60-E, 4T65-E

Oversized 1-2 & Reverse Servo Boost Valve Kit
Part No. 84754-40K

Fits either of 2 locations


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

In GM 4T60, 4T60-E and 4T65-E units, the continuous stroking of the 1-2 (Forward) and Reverse servo boost valves wear away at the valve bore, creating excess clearance and reduced apply pressures. This can lead to 1-2 band slippage, delayed engagements, 1-2 shift flares, and decreased Reverse pressure. Sonnax oversized 1-2 and Reverse servo boost valve kit 84754-40K that will restore the hydraulic integrity and more than doubles the valve-to-bore contact area to prevent leakage.

  • Hardcoat anodized aluminum valve combats premature wear
  • Valve will fit both the Forward and Reverse applications

This kit only contains one valve. If both bores need to be repaired, two kits are required.

  • Valve
  • Spring Long
  • Spring Short
  • Coiled Spring Pin

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.

GM 4T65-E Valve Body Layout

GM 4T65-E Valve Body Layout
  • 4T60, 4T60-E, 4T65-E Oversized 1-2 & Reverse Servo Boost Valve Kit 84754-40K
  • 4T60, 4T60-E, 4T65-E Oversized 1-2 & Reverse Servo Boost Valve Kit 84754-40K

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.

4T60, 4T60-E, 4T65-E Oversized 1-2 & Reverse Servo Boost Valve Kit Vacuum Test Locations