Sonnax 84754-30K, 4T65E Boost Valve Kit

$ 85.00


SKU: SX 84754-30K, Categories: , Tags: ,


4T65E Boost Valve Kit, Sonnax 84754-30K. 

Vehicles with GM 4T65-E transmissions often exhibit such problems as soft upshifts (especially 1-2), delayed Reverse and low line rise. The wear of the OE boost sleeve assembly can be traced back to this. The OE boost sleeve assembly consists of two steel valves and a steel plug that reside in the boost sleeve. The steel valves wear the aluminum sleeve and allow leakage of boost pressure. The OE boost assembly is not serviceable separately from OE, which forces the purchase of a new and expensive valve body. The Sonnax boost valve kit NUM0K enables you to replace the worn OE parts and saves the OE valve body, restoring the hydraulic integrity of the circuit.

  • Hardcoat anodized aluminum valves combat premature wear
  • The valves increase oil lubricity, center themselves, and prolong their own lifespan.
  • Line boost valve is longer than the OE valve to increase wear surface area
  • Sleeve is made of highly wear-resistant aluminum and has been designed with oil channels to evenly distribute boost valve oil
  • Drop-in Zip Valve™ parts install quickly and easily

  • Boost Valve & Sleeve Assembly


  • Erratic line pressure
  • Soft upshifts
  • Low line rise in Forward
  • Low line rise in Reverse


Bore wear near the small valve causes harsh or delayed Reverse depending on the location and severity of the leak, and the temperature wear near the end plug causes soft shift quality and low line rise.


Sonnax drop-in boost valve kit delivers oil 360° around the valve, reducing side-load. Also the surface contact of the spools is greater, which improves durability and reduces oil loss.

Additional information

Weight 1 lbs
Dimensions 4 × 4 × 2 in