The GM 6T75 is the six-speed automatic transaxle behind nearly every large GM crossover and front-wheel-drive sedan with a V6 engine built between 2007 and 2017. If you drive a Chevy Traverse, GMC Acadia, Buick Enclave, Saturn Outlook, Chevy Impala, Cadillac XTS, or Cadillac SRX, this is your transmission. GM designed the 6T75 as the heavy-duty member of their 6T transaxle family, built specifically to handle the torque output of their 3.6L V6 engine in vehicles that carry families and cargo every day.

The 6T75 has a well-documented design defect that GM acknowledged with a warranty extension — the 3-5-R wave plate failure. That single component has put more of these transmissions on our bench than any other issue. But wave plate failure is just the beginning. Torque converter shudder, valve body wear, and TEHCM module failures are close behind. We rebuild these with upgraded components that address every known weakness, starting with the wave plate that should have been redesigned before it ever left the factory.

The Failures We See Most on the 6T75

1. 3-5-R Wave Plate Failure

This is the failure the 6T75 is known for, and it is one of the most destructive single-component failures in any modern transmission. The 3-5-R clutch pack uses a steel wave plate — a dish-shaped spring that controls clutch apply pressure and piston travel. On early production units, GM did not stress-relieve these plates during manufacturing, leaving internal stress concentrated at the tab corners. Under normal driving conditions, the plate cracks at those stress points and breaks apart.

When the wave plate fractures, the broken steel fragments circulate through the transmission fluid and file down the splines on the 3-5-R clutch drum. The drum itself can crack. Those metal fragments then pass through the pump, contaminate the valve body, damage the torque converter, and attack the TEHCM module. What starts as one cracked plate turns into a cascading failure that can destroy every major component in the transmission. You lose third gear, fifth gear, and reverse because those are the gears the 3-5-R clutch pack controls.

GM eventually issued a warranty extension covering this condition up to 10 years and 120,000 miles on qualifying vehicles. In every 6T75 we rebuild, we install an upgraded stress-relieved wave plate and, when the drum is damaged, a drum reinforcement kit that salvages and strengthens the original drum rather than simply replacing it with another factory-spec part.

2. Torque Converter Shudder

The 6T75 torque converter develops a shudder between 30 and 50 miles per hour under light throttle as the lockup clutch material degrades. The Dexron VI fluid loses its friction modifier stability over time, especially if the transmission has been running hot, and the converter clutch begins chattering instead of locking smoothly. If the wave plate has already failed and sent metal through the system, the contamination accelerates converter deterioration significantly.

We replace the converter on every rebuild rather than attempting to clean and reuse the original. A reused converter with worn friction material or internal contamination is a comeback waiting to happen.

3. TEHCM Module Failure

The 6T75 uses an integrated TEHCM — the transmission control module, all shift solenoids, and pressure switches combined into a single unit that sits inside the transmission pan submerged in fluid. The laminated pressure switch films inside the module can delaminate over time, triggering false codes and erratic shift behavior. Heat and metal contamination from other failures accelerate the degradation. When any individual solenoid inside the TEHCM fails, the entire module typically must be replaced because the components are not individually serviceable.

On Generation 1 units (2007-2012), the TEHCM pressure switches were a particular weak point. GM redesigned the module for Generation 2 (2013+) and eliminated the pressure switches entirely. If your vehicle has a Gen 1 6T75, the TEHCM is one of the first components we evaluate during teardown.

What Goes Into a Top Notch 6T75 Rebuild

A dealer replacement on a 6T75 typically means a remanufactured unit from a warehouse line, inspected by someone who never sees how these transmissions actually fail in the field. Our rebuild is performed by technicians who know exactly where the weak points are and address every one of them:

• Upgraded 3-5-R wave plate — stress-relieved replacement that eliminates the fracture failure that destroyed the original. Drum reinforcement kit installed when the clutch drum shows spline or crack damage
• New or rebuilt torque converter — replaced on every build, verified for leaks, concentricity, and balance. Never cleaned and reused
• TEHCM evaluation and replacement when code history or internal inspection indicates laminate or solenoid degradation
• Valve body cleaning and solenoid testing — ultrasonically cleaned with each solenoid tested for response and holding pressure
• Upgraded clutch packs using friction material with higher heat resistance than factory specification
• Drive chain inspection — checked for stretch and wear, replaced when tolerances are out of specification
• Complete seal, gasket, and bushing replacement throughout the unit
• Cooler line flush — metal contamination from wave plate failure lives in the cooler circuit. Skipping this step contaminates the rebuild from day one
• Fresh Dexron VI fluid filled to specification

Every 6T75 rebuild is backed by our 3-year warranty and we offer financing to keep the repair manageable.

Frequently Asked Questions: 6T75 Transmission

What is the wave plate and why does it fail?

The wave plate is a dish-shaped steel spring inside the 3-5-R clutch pack that controls how the clutch piston engages. On early 6T75 units, GM did not stress-relieve the plate during manufacturing, so it cracks at the tab corners under normal driving conditions. When it breaks, the metal fragments circulate through the entire transmission and can destroy the clutch drum, pump, valve body, and converter. GM issued a warranty extension acknowledging the defect.

My Traverse lost reverse and third gear. Is that the wave plate?

Almost certainly. The 3-5-R clutch pack controls third gear, fifth gear, and reverse. When the wave plate fails and the clutch pack loses clamping ability, those are the gears that go first. If you also see a P0776 code, that further confirms the diagnosis. This requires a full rebuild, not just a clutch pack replacement, because the broken plate sends debris through the entire system.

Is the 6T75 the same as the 6T70?

They share the same architecture but the 6T75 is the higher-torque-capacity version, built for heavier vehicles like the Traverse, Acadia, and Enclave. The 6T70 serves lighter mid-size applications. They are not interchangeable. The wave plate failure affects both variants.

How much does a 6T75 rebuild cost?

A quality rebuild with upgraded wave plate, new converter, valve body reconditioning, and fresh clutch packs typically ranges from $2,500 to $4,000 depending on the extent of internal damage. Wave plate failures that have sent debris through the entire system cost more because more components need replacement. We offer financing to make the repair manageable.

Is it worth rebuilding the transmission in my Traverse or Acadia?

If the vehicle is otherwise in good condition, absolutely. A quality rebuild costs a fraction of replacing the vehicle and addresses the factory design defect with upgraded components. These are practical family vehicles that hold their value, and a rebuilt transmission with the corrected wave plate will outlast the original.

Vehicle Application Guide: GM 6T75 Transmission

GM Crossovers (Lambda Platform)

GM Sedans and Luxury

Note: The 6T75 pairs with the 3.6L V6 (and in some applications the 3.0L V6). AWD versions of the crossovers use a power take-off unit bolted to the transaxle. We rebuild both FWD and AWD configurations.

Ready to Fix Your 6T75 for Good?

Call Top Notch Transmissions today at (817) 386-7592 to schedule a diagnostic. We offer free estimates, a 3-year warranty on all rebuilds, financing to fit your budget, and free towing anywhere in DFW.