Symptoms:

  • 2nd Gear starts
  • Low AFL pressure
  • 3rd Clutch failure
  • 3-4 Concerns

Cause:

Wear at the shift valve spools and bore lands allows loss of critical hydraulic pressure. Typically wear is most severe at the signal A spool/land.

Correction:

Recondition the bore and install Sonnax oversized 3-4 shift valve kit.

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

Oversized 3-4 Shift Valve Kit
Part No. 77754-42K


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

In GM 4L60-E, 4L65-E abd 4L70-E units, wear at the shift valve spools and bore lands causes loss of critical hydraulic pressure which, depending on the wear location and severity, can result in shift timing/feel complaints, 2nd Gear starts, 3rd clutch failure, 3-4 shift complaints and loss of AFL pressure. Reconditioning the bore and installing Sonnax oversized 3-4 shift valve kit 77754-42K restores hydraulic integrity.

  • Hardcoat anodized aluminum valve combats premature wear
  • Sonnax spring maintains OE operating pressures and timing
  • Valve
  • Spring
  • 4L60-E, 4L65-E, 4L70-E Oversized 3-4 Shift Valve Kit 77754-42K
  • 4L60-E, 4L65-E, 4L70-E Oversized 3-4 Shift Valve Kit 77754-42K

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 3-4 Shift Valve Kit Vacuum Test Locations