Symptoms:

  • High line pressure in Reverse
  • Low line rise
  • Gear ratio codes
  • TCC slip
  • Flare shifts

Cause:

The boost sleeve increases line pressure for shift quality, engagement and proper TCC apply. As the sleeve wears, torque signal oil will leak to exhaust and line pressure will not increase as commanded.

Correction:

Sonnax boost valve kits restore proper clearance with upgraded design and material to prevent EPC and Reverse boost loss. Increased performance and OE ratio kits are available.
  • 5L40-E, 5L50-E Boost Valve Kit 55209-04K
  • 5L40-E, 5L50-E Boost Valve Kit 55209-04K
  • 5L40-E, 5L50-E Boost Valve Kit 55209-04K details

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.

5L40-E, 5L50-E Boost Valve Kit Vacuum Test Locations