• Poor shift quality
  • Soft shifts
  • Low line rise
  • Erratic buzz
  • Premature clutch failure
  • Premature band failure
  • Uncontrolled pressure in Reverse
  • Low Reverse boost


Regulator valve wear allows critical fluid loss that results in driveability concerns.


Renew pressure regulator performance and revive line pressure control by installing Sonnax main pressure regulator valve.


Main Pressure Regulator Valve
Part No. 76948-01

Replaces '95-Earlier 4-spool valves only. DOES NOT replace 3-spool valves.

You need this if... View Instructions Find a Distributor

Vehicles with 4R70W and AODE transmissions often have erratic line pressure, poor line rise and/or throttle-sensitive buzz. This can result in harsh or soft shifts and band/clutch failure as well as other driveability concerns. Worn pressure regulator valve spools allowing pressure escape are a common problem in these units. Installing Sonnax main pressure regulator valve 76948-01 restores normal line pressure operation in all ranges.

If bore is excessively worn, install Sonnax oversized pressure regulator and boost valve kit 76948-16K.

  • Hardcoat anodized aluminum valve combats premature wear
  • Annular grooves help center valve in bore to reduce side-loading
Learn More About Zip Valve™ Drop-In Repairs

'91–'95 PR valve and '96-later PR valve designs are not interchangeable. For '96-later PR valve, see 76948-09.

  • 4R70W, AODE Main Pressure Regulator Valve 76948-01
  • 4R70W, AODE Main Pressure Regulator Valve 76948-01

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.

4R70W, AODE Main Pressure Regulator Valve Vacuum Test Locations