Tool Required

Printpartsummary
Symptoms:
  • 1-2 Long
  • Flare shifts
  • Soft shifts & poor line rise
Cause:

Wear at the 1-2 accumulator valve and/or bore, allowing loss of torque signal, 1-2 accumulator and/or line pressure.

Correction:

Refurbish the worn bore and install the Sonnax oversized valve to restore correct hydraulic clearances.

Tool Required

4T65-E

Oversized 1-2 Accumulator Valve

Part No.

84754-57K

Oversized 1-2 Accumulator Valve
  • 84754-57k_combo

  • Oversized 1-2 Accumulator Valve

Small_84754-57k_combo Small_84754-57k

4T65-E

Oversized 1-2 Accumulator Valve

Part No. 84754-57K

Fits GM and Volvo applications.

Complaint:

  • 1-2 Long
  • Flare shifts
  • Soft shifts & poor line rise

Cause:

Wear at the 1-2 accumulator valve and/or bore, allowing loss of torque signal, 1-2 accumulator and/or line pressure.


Correction:

Refurbish the worn bore and install the Sonnax oversized valve to restore correct hydraulic clearances.

To help control the 2nd clutch apply pressure and shift feel in the 4T65-E, a 1-2 accumulator piston and accumulator valve regulating fluid pressure are used. The 1-2 accumulator valve regulates line pressure using torque signal influence and directs 1-2 accumulator pressure to the spring side of the piston, controlling the 2nd clutch apply. Wear at the bore or valve can allow torque signal, 1-2 accumulator or line pressures to exhaust, resulting in various 1-2 shift complaints. The oversized Sonnax valve is made from wear-resistant, hard-coat anodized aluminum to prevent future wear in a refurbished bore. Annular grooves have been added to the valve spool to hydraulically center the valve in the bore for wear resistance.

  • Valve is hard-coat anodized to prevent wear
  • Can be used in either early- or late-style valve bodies.
  • Annular grooves added for hydraulic centering and wear reduction
WARNING:

Required tool kit F-84754-TL57 is no longer in production. Check with your distributor for availability.

Required Tools

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.

  • Test Locations

Click here to view PDF if instructions do not appear below.

It appears you don't have a PDF plugin for this browser. Click here to view the PDF file.

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

Related Tech Articles

Sonnax

GM 4T65-E Vacuum Test Guide

Contact a Sonnax Distributor to purchase this part.