4L80-E, 4L85-E

Heavy Duty Remanufactured Valve Body
Part No. GM033

Fits '97-'03 units. Smart-Tech® overrun clutch valve kit installed.

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Sonnax heavy duty remanufactured valve body GM033 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

  • 4L80-E, 4L85-E Heavy Duty Remanufactured Valve Body GM033

GM 4L80-E Valve Body Identification

Part Number Chart

Part NumberDescription
[GM026] (Warranty Only)'91-'92 with Screw-In Temp Sensor
GM027'92-'96 Temp Sensor in Wire Harness
GM028'97-'03
GM029'04-Later


Identification

'91-'96

Look for two small holes on the upper right side of the valve body. The holes do not appear on '97-later units.

The screw in the temperature sensor is only used in 1991. All later years use the temperature sensor located in the internal wiring harness.

'97-'03
The lube hole moved to the location
indicated by the arrow above.
'04-Later
Have a late-style EPC, which can be identified by the silver canister.