• Low Reverse boost


Worn and leaking boost sleeves.


Sonnax drop-in Reverse boost valve kit provides more sealing area. Sleeves and valves made from high-quality hardened steel to prevent excess wear.

4T60, 4T60-E

Reverse Boost Valve Kit
Part No. 84754-14K

Low ratio, .273" dia. small spool

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

Vehicles with GM 4T60 or 4T60-E transmissions often exhibit such problems as poor line rise, soft shifts, poor Reverse boost and/or 2nd and 3rd clutch distress. These problems can often be caused by worn and leaking boost sleeves. The OE boost valve spools have very narrow contact surfaces within the sleeves, which contribute to the leakage. Sonnax Reverse boost valve kit 84754-14K restores hydraulic integrity.

  • Sleeves and valves are made from high-quality, hardened steel to resist wear
  • Valve spools have been lengthened considerably to provide more sealing area with the sleeves
  • Kit includes a replacement spring to provide proper calibration for the lengthened valve spools
  • Drop-in Zip Valve™ parts install quickly and easily
Learn More About Zip Valve™ Drop-In Repairs
  • Valve
  • Sleeve
  • Spring

Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.

GM 4T60, 4T60-E Valve Body Layout

GM 4T60, 4T60-E Valve Body Layout
  • 4T60, 4T60-E Reverse Boost Valve Kit 84754-14K
  • 4T60, 4T60-E Reverse Boost Valve Kit 84754-14K

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.

4T60, 4T60-E Reverse Boost Valve Kit Vacuum Test Locations