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 kit76948-16K.

• Hardcoat anodized aluminum valve combats premature wear
• Annular grooves help center valve in bore to reduce side-loading