Description
4R70W / AODE Main Pressure Regulator Valve, Sonnax 76948-01.
Replaces ’95-Earlier 4-spool valves only. DOES NOT replace 3-spool valves.
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 drive ability 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
’91–’95 PR valve and ’96-later PR valve designs are not interchangeable. For ’96-later PR valve, see 76948-09
Symptoms:
- Poor shift quality
- Soft shifts
- Low line rise
- Erratic buzz
- Premature clutch failure
- Premature band failure
- Uncontrolled pressure in Reverse
- Low Reverse boost
Cause:
Regulator valve wear allows critical fluid loss that results in driveability concerns.
Correction:
Renew pressure regulator performance and revive line pressure control by installing Sonnax main pressure regulator valve.
