• Low line rise
  • Soft shifts
  • 2nd Clutch distress
  • 3rd Clutch distress


Worn and leaking boost sleeves


This  replacement boost valve kit provides more sealing area. Sleeves and valves made from high-quality hardened steel to prevent excessive wear.

4T60, 4T60-E

Modulated Line Boost Valve Kit
Part No. 84754-12K

Low Ratio, .276" dia. small spool

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Vehicles with 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.

  • 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 kits 84754-24K & 84754-25K allow replacement of all items together
  • Valve
  • Sleeve
  • Spring
  • 4T60, 4T60-E Modulated Line Boost Valve Kit 84754-12K
  • 4T60, 4T60-E Modulated Line Boost Valve Kit 84754-12K