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 modulated line boost valve kit 84754-12K 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
• Combined kit 84754-24K allow replacement of all items together
• Drop-in Zip Valve™ parts install quickly and easily