Sonnax heavy duty remanufactured valve body GM030 has been designed with the workhorse vehicle in mind. Featuring the Sonnax patented 34200-40K Smart-Tech overrun clutch valve kit pre-installed, this valve body corrects the issue of insufficient holding power by the overdrive roller clutch, the underlying cause of chronic overdrive roller clutch failure in 4L80-E units.

This heavy duty remanufactured valve body also includes all new solenoids and a new pressure switch assembly. Chronic wear points in the valve body have also been repaired by reaming and installing top-quality oversized Sonnax valves that optimize valve body function and prevent future wear. These updates correct the common symptoms of wrong gear starts, clutch and band failure, solenoid performance codes, 2-3 neutral, TCC apply and release concerns, TCC and other trouble codes, and various shift complaints.

To guarantee the highest level of operational performance, this remanufactured valve body is tested on state-of-the-art equipment to verify that actuator feed limit pressure, clutch pressures, and torque converter pressures meet the necessary requirements for optimum functionality.

• Smart-Tech overrun clutch valve kit 34200-40K is pre-installed for unrivaled durability
• All-new solenoids (EPC, Shift A & B, PWM TCC) and new pressure switch assembly correct shift complaints
• Chronic wear points including AFL, TCC regulator and accumulator control valves are corrected by refurbishing the bore and installing Sonnax oversized valves
• 3rd and Reverse checkball sleeves are also replaced as the OE wear over time