6T70 Rebuild Cost and What Drives It

Two shops can look at the same Traverse with no reverse and hand back estimates that are a thousand dollars apart, and both can be honest. A 6T70 rebuild price is not one number. It is a labor block that barely moves, a soft-parts kit that barely moves, and then a list of hard parts, valve body work and converter decisions that swing the total. If you know which of those line items are fixed and which depend on what the teardown finds, you can read any estimate and know whether it makes sense.

This guide uses GM's own warranty labor times and parts lists, Sonnax's failure analysis and ATRA's service notes for the 6T70/6T75 in the Acadia, Enclave, Traverse, Outlook, Equinox, Terrain, Malibu, Impala, LaCrosse, SRX and XTS. Everything is listed in the Sources at the end.

Recommended 6T70 parts

The fixed part of every 6T70 rebuild: the master kit for your generation (check the RPO, 2013 was built both ways) and the filter that GM and ATRA say goes in after any internal repair.

6T70 Transmission Master Rebuild Kit Gen 2 2013-Up

$447.99View part

6T70 Gen 1 Master Rebuild Kit with Pistons 2007-2012

$367.99View part

6T70/6T75 Transmission Filter and Pan Gasket Kit 24223670

$39.99View part

The part that does not move: labor

The best published number for 6T70 teardown labor comes from GM itself. When GM paid dealers to fix the broken 3-5-Reverse wave plate under Special Coverage 14404B, it allowed 11.5 hours on front-wheel drive and 12.3 hours on all-wheel drive, and that time includes all associated parts, cleaning and flushing, and a front end alignment. The alignment line tells you this is a front-end-disturbing job, and the AWD time is higher because there is more driveline to remove before the transaxle comes out.

That job is not a full rebuild. It is a remove, separate the case halves, replace one clutch pack and its housing parts, clean, and reinstall. A true rebuild, where every clutch pack, seal and gasket is replaced and the valve body is serviced, takes at least that much time and usually more bench time on top. So when a shop quotes somewhere in the low-to-mid teens of hours for a 6T70 R&R and rebuild, that is in line with GM's own clock, not padding.

To turn that into dollars, multiply by the shop's posted labor rate. Ask whether the shop bills flat-rate hours (an independent or manufacturer's estimate of the time a job takes) or actual time worked on the ticket — the two numbers are rarely the same, and you want to know which one you are agreeing to before you sign anything. As a worked example only: at a $150 per hour door rate, 11.5 hours is $1,725 and 12.3 hours is $1,845 before a single part.

The parts that barely move: the soft-parts kit

Every rebuild uses a master kit: frictions, steels, seals, gaskets and the valve body separator gaskets. Master kits for the 6T70 generally run a few hundred dollars. On our own shelf the Gen. 1 master kit with pistons is $367.99 and the Gen. 2 master kit is $447.99. The number that matters more is generation. ATRA notes that the 6T70 (RPO M7W or M7U) and 6T75 (RPO M7V and M7X) got a major control system update for the 2013 model year, and other RPO applications did not get it until 2014 production. A 2013 can be either one. Check the RPO on the service parts label and order to that, or you will pay twice.

Add fluid. The 6T70 takes DEXRON VI only, and a rebuild means an overhaul fill plus flushing the cooler, so budget for more than a pan drop's worth. ATRA also points out that the 6T70 filter is non-serviceable and is only replaced after internal repair, so a rebuild is exactly when a new filter goes in, and it belongs on the estimate.

The parts that swing the total: hard parts

The 3-5-R wave plate and drum

This is the 6T70's signature failure and the biggest single swing item. GM bulletin 09-07-30-012F describes a broken 3-5-R clutch wave plate letting the apply piston over-stroke, which leaks and causes loss of apply: no reverse, a slip or flare in 3rd or 5th, and DTC P0776, often with P0777, P2723, P0716, P0717, P2715 or P2714. GM says it normally does not happen before about 20,000 miles, and that the debris it makes can affect the speed sensors and other clutches.

GM's release is a new waved plate, P/N 24254103, and the bulletin recommends installing a new plate any time the transmission is disassembled for any reason. That is a cheap part. The expensive part is what the broken plate did on the way out. Sonnax's failure study found every broken OE plate separated at a tooth corner, and notes that when the plate breaks apart it usually damages the drum splines, requiring an expensive new housing. Sonnax also points out that stock and rebuilt units with the updated shot-peened GM plate, Gen. 2 included, are still failing in the field. Its 124555K drum saver kit uses a toothless waved plate guided by a billet cupped steel and can salvage a drum that has already been chewed.

Collateral damage GM itself budgeted for

Special Coverage 14404B lists the required kit (seal kit, fiber and steel reverse clutch plates, reverse clutch housing, reverse clutch piston, 3-5 reverse backing plate and DEXRON 6), then a second list of parts that are only replaced if they are worn or damaged: the reaction sun gear, the 6T75 reaction carrier, the 3-5 reverse backing plate retaining ring, the case cover, the low and reverse clutch piston, the 2-6 clutch spring and the 2-6 clutch piston. GM estimated that some of those parts would be needed in approximately 25 percent of the repairs. That is the best real-world figure available for how often a 6T70 teardown turns up more than the kit covers, and it comes straight from the manufacturer's warranty budget.

The case cover is its own line. ATRA's service notes tell you to measure the case cover hub, and if the distance is too great, replace the case cover. GM's bulletin says to inspect the case cover for damage from the broken plate and notes it is serviced separately. Peening or wear on the case lugs that drive the steels, on the other hand, is normal per GM and is not a reason to replace the transmission.

The valve body

Valve body work can be a few vacuum-tested bores or two new castings. For 2014-2019 units with launch shudder, 4th gear shudder or a 2-3/3-2 shudder, GM bulletin 18-NA-358 blames debris or scored valves in the upper and lower valve bodies and calls for replacing both at the same time: upper 24281084 and lower 24257450, with valve body kit 24264343 or 24268463 depending on RPO. It also says TEHCM replacement has not been an effective repair for that condition. An estimate that includes a TEHCM for a shudder complaint deserves a question. We break down valve-by-valve symptoms in our 6T70 valve body guide.

The torque converter

Many quotes add a converter by default. GM gives a rule for when it is needed. Per 09-07-30-012F, fine metal particles you cannot feel, traces of flakes or a gray color to the fluid, are not reasons to replace the converter. Metal chips you can feel, or debris found in the converter or while flushing the cooler and lines, mean it should be replaced. ATRA adds that some 6T70 converters show a dark or blue discoloration on the hub side, and if the whole converter is not discolored, that alone is not a reason to replace it. When the converter does come out, ATRA says it has to be lifted vertically with J-46409 because its lip seal lives inside the converter and is damaged if it is removed or installed horizontally. A converter that was dropped in sideways is a comeback, and a comeback costs more than any converter.

The line items people forget

• TCM programming. ATRA: the TCM is internal to the transaxle, so any time you replace the transaxle, or the TEHCM, the TCM has to be programmed. That is scan tool time and, at some shops, a separate charge.
• Relearn and road test. Service Fast Learn Adapts and a hot road test are part of doing the job right. A rebuild that skips the learn can shift badly with every new part in it.
• Cooler flush. 09-07-30-012F says debris must be cleaned from the entire transmission and that failing to separate the case halves, clean the debris and replace the pump fluid filter and the control solenoid filter plate could lead to repeat damage. Cleaning the cooler circuit is the same logic.
• Alignment. GM includes it in its own labor operation. If your shop's quote does not, ask.

Is the GM special coverage still an option?

For almost everyone, no. Special Coverage 14404B covered 2007-2009 Enclave, Acadia, Outlook, Aura, G6, 2008-2009 Equinox, Malibu, Torrent and Vue, and 2009 Traverse with RPO MH2, MH4, MH6 or MY9 for 10 years or 120,000 miles from the original in-service date, whichever came first. Even the last 2009 models are past the 10-year mark now, so the plate job is on the owner or a service contract. It is still worth asking a dealer to check the VIN for any open campaigns before paying for teardown.

Rebuild, reman or used: where the money goes

In-house rebuild. You pay labor plus the kit, the filter, fluid and whatever hard parts the teardown finds. On a clean unit caught early, it is the lowest number. On a unit with a shattered wave plate and a chewed drum, the hard parts add up quickly, and you only find out after the case is split.

Remanufactured unit. The unit price is higher, but the hard-parts gamble is off the table and the R&R labor is less than a rebuild because nobody is on the bench. You still pay for programming, fluid and the cooler flush. Match the generation and RPO exactly.

Used unit. Cheapest up front and a coin flip otherwise. On a 2007-2009 Gen. 1, a used unit that has never had the wave plate replaced is carrying the same failure you are trying to get away from.

How to read a 6T70 estimate

California's Bureau of Automotive Repair publishes the cleanest version of this advice, and it applies no matter what state you are in: get a written estimate that identifies the condition to be repaired, the parts needed and the anticipated labor charge, and keep a signed copy. A transmission job is specifically called out in BAR's consumer guide as a case that often needs a teardown estimate — the shop has to take the unit apart to see what is actually wrong before it can quote the repair. You can be charged for that teardown even if you decide not to proceed, so ask up front what it costs. A proper teardown estimate has to disclose that the transaxle may not be reassembled-as-is, what reassembly costs if you walk away, and how long reassembly takes. Once the teardown is done, the shop owes you a revised written estimate before any repair work starts, and if the job grows past that number once it is underway, the shop has to contact you again and record your approval — your name, the date and time, and what was authorized — before charging for the added work. For a 6T70 specifically, check that the estimate:

1. Names the generation and RPO, not just the model year.
2. Lists the updated 3-5-R waved plate (or a drum saver kit) even if the complaint is not reverse, since GM recommends a new plate any time the unit is apart.
3. Explains any converter charge in terms of what was found, not by default.
4. Includes the filter, fluid, cooler flush, TCM programming and relearn.
5. Gives a hard-parts allowance or a call-before-you-buy rule, because roughly one in four of these repairs needs more than the kit.

FAQ

How many labor hours is a 6T70 rebuild?

GM's own warranty labor time for the 3-5-Reverse clutch plate job in Special Coverage 14404B, which requires pulling the transaxle and separating the case halves, is 11.5 hours on front-wheel drive and 12.3 hours on all-wheel drive, including cleaning, flushing and a front end alignment. A full rebuild with more clutch packs, a valve body and a converter takes at least that much bench and R&R time.

Is the GM 6T70 wave plate special coverage still active?

Special Coverage 14404B ran 10 years or 120,000 miles from the original in-service date on 2007-2009 models. Every covered vehicle is now past the 10-year limit, so the repair is paid by the owner or a service contract today.

Does a 6T70 rebuild always need a new torque converter?

No. GM bulletin 09-07-30-012F says fine metal particles you cannot feel are not a reason to replace the converter, while chips you can feel, or debris found in the converter or cooler lines, are. ATRA also notes that blue or dark discoloration on the hub side alone is not a reason to replace it.

Why do some 6T70 rebuild quotes come in much higher than others?

Hard parts. GM estimated that roughly 25 percent of wave plate repairs needed parts beyond the plate kit, such as the reaction sun gear, reaction carrier, case cover or pistons, and a broken wave plate often damages the 3-5-R drum splines. Add a valve body replacement or converter and the parts bill can double.