Symptoms:

  • No 4th
  • 2-4 Band burned
  • Low 4th Gear pressure

Cause:

Continuous oscillation in sequence valve bore causes wear that prevents proper hydraulic control.

Correction:

Recover hydraulic control and renew 4th gear operation by reconditioning the bore and installing Sonnax oversized 4-3 sequence valve kit.

Warning:

This kit does not address wear on the inboard two spools. To address wear in that location, use Sonnax oversized 4-3 sequence valve kit 77964-14K.

4L60-E, 4L65-E, 4L70-E

Oversized 4-3 Sequence Valve Kit
Part No. 77964-04K


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

GM 4L60-E, 4L65-E and 4L70-E transmissions often have trouble shifting into or holding 4th Gear due to excess wear in the sequence valve bore. This wear allows vital 4th Gear accumulator oil to exhaust, resulting in deficient servo apply pressure. Consequences are slipping or no 4th Gear operation followed closely by a burnt band. Leaking at the OE end plug also allows oil loss that can leave 4th Gear inoperable. Re-establish hydraulic control and restore normal operation by reconditioning the bore and installing Sonnax oversized 4-3 sequence valve kit 77964-04K.

  • O-Ringed end plug helps prevent 4th Gear oil loss
  • Hardcoat anodized aluminum valves combat premature wear
  • 3-4 Relay Valve
  • 4-3 Sequence Valve
  • End Plug
  • O-Ring
  • 4L60-E, 4L65-E, 4L70-E Oversized 4-3 Sequence Valve Kit 77964-04K
  • 4L60-E, 4L65-E, 4L70-E Oversized 4-3 Sequence Valve Kit 77964-04K

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.

4L60-E, 4L65-E, 4L70-E Oversized 4-3 Sequence Valve Kit Vacuum Test Locations