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 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