GM 6T70 Wave Plate Failure: No Reverse in Traverse, Acadia and Enclave

By Auto Part Ocean Editorial · Updated October 25, 2026

What is the GM 6T70 wave plate failure? On the 6-speed automatic used in many 2007–2009 GM crossovers and sedans, including the Chevrolet Traverse, GMC Acadia, Buick Enclave and Saturn Outlook, the 3-5-Reverse clutch wave plate can crack or break. When it does, you lose 3rd, 5th and reverse, usually with a check engine light. GM issued an updated plate and later a special coverage of 10 years or 120,000 miles, but that coverage has now expired. If your transmission has failed, a tested used, rebuilt or remanufactured 6T70 or 6T75 usually costs far less than a dealer replacement.

These family crossovers were huge sellers, so many are still on the road with high miles. If yours suddenly won't go into reverse, this is the first thing to suspect.

Which GM vehicles have the 6T70 wave plate problem?

GM's special coverage bulletin 14404A lists these vehicles with the 6T70 or 6T75 front or all-wheel-drive 6-speed automatic:

1. 2007–2009 GMC Acadia
2. 2007–2009 Buick Enclave
3. 2007–2009 Saturn Outlook and Aura
4. 2007–2009 Pontiac G6 (V6 versions)
5. 2008–2009 Chevrolet Equinox and Malibu (V6 versions)
6. 2008–2009 Pontiac Torrent and Saturn Vue (V6 versions)
7. 2009 Chevrolet Traverse

Later vehicles use the same transmission family with an updated wave plate, so they're much less likely to have this specific failure. Always confirm your transmission against your VIN.

What causes the 3-5-Reverse wave plate to break?

A wave plate is a thin, wavy steel ring inside a clutch pack. It cushions the clutch as it applies. GM's service bulletin 09-07-30-012F explains what happens when the 3-5-Reverse (35R) wave plate breaks:

1. The broken plate lets the clutch apply piston over-stroke and leak.
2. The clutch loses its apply pressure, so 3rd, 5th and reverse stop working.
3. Pieces of the broken plate circulate as debris, which can affect the speed sensors and other clutches.

GM said the failure normally didn't occur before about 20,000 miles. Older plates weren't as durable, and GM released an updated design.

What are the symptoms of a broken 6T70 wave plate?

From GM's bulletins, watch for:

1. No reverse, often the first thing owners notice.
2. No 3rd or 5th gear, or a slip or flare when shifting into them.
3. Harsh shifts into 3rd or 5th.
4. The check engine light, often with code P0776 (clutch pressure control solenoid 2 stuck off).
5. Other codes such as P0777, P0716, P0717, P2714, P2715 or P2723.

If your Acadia, Traverse or Enclave won't reverse, stop driving it and have it diagnosed. Debris can spread damage the longer it runs.

Is GM's 6T70 wave plate coverage still active?

No. GM's special coverage 14404A covered the 3-5-Reverse clutch plate replacement at no charge for 10 years or 120,000 miles from the original in-service date, whichever came first. The repair included replacing the plate, cleaning out debris, and replacing the pump fluid filter and control solenoid filter plate.

Even the newest 2009 models are now well past 10 years, so the coverage has ended. Repairs today are at the owner's cost.

How much does it cost to fix a 6T70?

Kelley Blue Book's dealer estimate for replacing the transmission on a 2009 Chevrolet Traverse near Dallas, Texas is about $7,425 to $7,915, including roughly $5,952 to $6,320 in parts and $1,473 to $1,595 in labor.

Other options cost less:

1. Wave plate repair: the transmission has to come out and be cleaned, so labor is significant, and debris damage can add more.
2. Tested used 6T70 or 6T75: usually far less than a dealer replacement, plus installation.
3. Rebuilt or remanufactured unit: costs more than used, but with fresh internal parts and the updated plate.

Why do some 6T70 repairs fail again?

A wave plate repair only works if all the debris is removed. GM's bulletin calls for:

1. Cleaning the entire transmission of debris.
2. Replacing the pump fluid filter and control solenoid filter plate.
3. Inspecting the case, pump, clutch housing and torque converter.
4. Cleaning the speed sensors.

If metal pieces are left behind, they can damage the replacement parts. That's why many owners choose a complete replacement transmission on a high-mileage vehicle.

Where are 6T70 GM crossovers most common in the US?

There's no public state-by-state failure data for this problem, so we won't make any up. But these GM crossovers are especially common in some states, and some use is harder on transmissions.

Big GM crossover states

1. Michigan
2. Ohio
3. Illinois
4. Indiana
5. Pennsylvania
6. Wisconsin

Towing, heat and big families

1. Texas
2. Oklahoma
3. Kansas
4. Missouri
5. Tennessee
6. Arizona

Heavy loads, towing and heat all raise transmission temperatures, so regular fluid service matters on these crossovers.

Repair the 6T70 or replace it?

Targeted repair

• What it involves: replacing the 3-5-Reverse wave plate, cleaning debris and replacing filters
• Best when: the vehicle is in great shape, mileage is reasonable and the failure was caught early
• Watch out for: debris damage elsewhere can turn a plate job into a full rebuild

Used, rebuilt or remanufactured 6T70/6T75

• What it involves: replacing the transmission with a tested unit
• Best when: there's heavy debris, high mileage, or other clutches are damaged
• Watch out for: matching 6T70 vs 6T75, FWD or AWD, and the right model year to your VIN

Auto Part Ocean (www.autopartocean.com) carries 6T70 and 6T75 transmissions in used, rebuilt and remanufactured condition for the Traverse, Acadia, Enclave and more, and every quote is checked against your VIN first.

Where can you buy a replacement 6T70 in the US?

Five common places to look:

1. LKQ: A large North American recycled OEM parts network, with Pick Your Part yards. Best for: a wide choice of used factory transmissions.
2. AutoZone: The largest auto parts retailer in the US. Best for: fluid, filters and transmission coolers.
3. RockAuto: An online-only catalog. Best for: pricing wave plates, filters and rebuild kits.
4. Auto Part Ocean: Transmissions and engines for 60+ makes in used, rebuilt and remanufactured condition, VIN-matched and shipped across the US. Best for: a complete 6T70 or 6T75 with your choice of condition.
5. FNP Auto Parts: Tested used transmissions and engines for Japanese brands, VIN-checked before sale. Best for: Honda Pilot, Toyota Highlander and Nissan Pathfinder owners.

If you also have a Japanese SUV in the driveway, FNP Auto Parts (www.fnpautoparts.com) is worth checking for Japanese transmissions.

How to replace a 6T70 the right way

Step 1: Diagnose properly. Confirm the codes and check the pan for wave plate fragments.

Step 2: Match the replacement to your VIN, including 6T70 or 6T75, FWD or AWD, and model year.

Step 3: Make sure the replacement has the updated wave plate, especially if it came from a 2007–2009 donor.

Step 4: Flush the cooler and lines so old debris doesn't reach the new unit.

Step 5: Program and relearn the transmission after installation if required.

Step 6: Keep every receipt. Many warranties, including ours, ask for proof of professional installation and correct fluid.

Mistakes 6T70 owners make

The expensive one is continuing to drive after losing reverse, which spreads debris through the transmission.

Others include skipping the cooler flush, buying a used 2007–2009 unit without asking about the wave plate, and ignoring a check engine light with transmission codes.

Questions to ask your transmission supplier

Is this a 6T70 or 6T75, and does it match my VIN? They're related but not always interchangeable.

Does it have the updated 3-5-Reverse wave plate? Ask directly.

Has it been tested, and what's the mileage? Ask for details.

What does the warranty require? Ask about fluid, programming and installation.

Frequently asked questions

What is the 6T70 wave plate problem? On many 2007–2009 GM crossovers and sedans, the 3-5-Reverse clutch wave plate in the 6-speed automatic can crack or break, causing loss of 3rd, 5th and reverse gears.

Which vehicles have the 6T70 wave plate issue? GM's coverage listed the 2007–2009 Acadia, Enclave, Outlook, Aura and G6, 2008–2009 Equinox, Malibu, Torrent and Vue, and the 2009 Traverse.

Why won't my GMC Acadia go into reverse? On 2007–2009 models, a broken 3-5-Reverse wave plate is a common cause, often with code P0776 and no 3rd or 5th gear.

Is GM's 6T70 extended warranty still valid? No. The special coverage ran for 10 years or 120,000 miles from the in-service date, and all affected vehicles are now past it.

How much does it cost to replace a Chevy Traverse transmission? Kelley Blue Book's dealer estimate for a 2009 Traverse near Dallas is about $7,425 to $7,915. A tested used or remanufactured unit usually costs much less.

The bottom line

The 6T70 wave plate failure is a well-known problem on 2007–2009 GM crossovers, and the factory coverage has ended. If yours has lost reverse, 3rd or 5th, a tested used, rebuilt or remanufactured 6T70 or 6T75 matched to your VIN is usually the smartest way to get your vehicle back on the road.

Want a price on a 6T70? Have your VIN ready and call Auto Part Ocean (www.autopartocean.com) at +1-888-819-5651, or browse our transmissions.

Sources

• Affected vehicles, symptoms and 10-year/120,000-mile special coverage: GM special coverage 14404A via NHTSA
• Cause, codes and repair procedure: GM service bulletin 09-07-30-012F via NHTSA
• Dealer replacement estimate: Kelley Blue Book, 2009 Chevrolet Traverse transmission repair and replacement
• Warranty installation requirements: Auto Part Ocean warranty policy

Auto Part Ocean (www.autopartocean.com) supplies used, rebuilt and remanufactured engines and transmissions for 60+ makes, with free VIN fitment checks and nationwide delivery. Learn more about us.