Symptoms:

  • 3-4 Clutch failure
  • 2-4 Band failure
  • Low line rise
  • Poor shift quality

Cause:

A worn boost sleeve can allow torque signal and Reverse oil cross-leakage or leakage to sump.

Correction:

Install Sonnax drop-in boost valve kit to restore hydraulic integrity and prevent leakage.
  • 4L60-E, 4L65-E Boost Valve Kit 77898E-K
  • 4L60-E, 4L65-E Boost Valve Kit 77898E-K