Tool Required

Printpartsummary
Symptoms:
  • 1-2 Band burned
  • 1-2 Flare
  • Delayed engagement
  • Low Reverse pressure
Cause:

These complaints may be caused by the continuous reciprocation of the 1-2 (forward) and reverse servo boost valves wearing the valve body bores.

Correction:

This oversized, hard-coat anodized aluminum valve restores hydraulic integrity, and has increased valve-to-bore contact to prevent leakage. This valve requires the use of a Sonnax reaming tool kit.

Tool Required

4T60, 4T60-E, 4T65-E

Oversized 1-2 & Reverse Servo Boost Valve Kit

Part No.

84754-40K

Oversized 1-2 & Reverse Servo Boost Valve Kit
  • 84754-40k_combo

  • Oversized 1-2 & Reverse Servo Boost Valve Kit

Small_84754-40k_combo Small_84754-40k

4T60, 4T60-E, 4T65-E

Oversized 1-2 & Reverse Servo Boost Valve Kit

Part No. 84754-40K

  • Valve
  • Long Spring
  • Short Spring
  • Coiled Spring Pin

Fits either of 2 locations

Complaint:

  • 1-2 Band burned
  • 1-2 Flare
  • Delayed engagement
  • Low Reverse pressure

Cause:

These complaints may be caused by the continuous reciprocation of the 1-2 (forward) and reverse servo boost valves wearing the valve body bores.


Correction:

This oversized, hard-coat anodized aluminum valve restores hydraulic integrity, and has increased valve-to-bore contact to prevent leakage. This valve requires the use of a Sonnax reaming tool kit.

The continuous stroking of the 1-2 (forward) and reverse servo boost valves wear away at the valve bore, creating excess clearance and reduced apply pressures. This can lead to 1-2 band slippage, delayed engagements, 1-2 shift flares, and decreased reverse pressure. Sonnax has developed an oversized valve 84754-40K that will restore the hydraulic integrity and more than doubles the valve-to-bore contact area to prevent leakage.

  • Valve is manufactured from hard-coat anodized aluminum to prevent future bore wear.
  • Valve will fit both the forward and reverse applications for the 4T60, 4T60-E and 4T65-E
NOTE:

This kit only contains one valve. If both bores need to be repaired, two kits are required.

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Valve Body Layouts

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.

Valve Body Layout GM 4T65-E

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