6T40 Clutch Drum 2008, new and ready to install. Fits the 6T40. Ships fast from the USA.
If your Cruze, Malibu, Sonic or other 6T40-equipped GM is stuck in third, flares on the 3-4 shift, or came apart with a chewed-up clutch drum on the bench, this is the hard part you are looking for. It is a new, aftermarket 4-5-6 clutch drum assembly for the 6T40, listed for 2008 and later units. It comes with the drum, a wave plate, a pressure plate and the snap ring, and it has 36 outer lugs to carry the 4-5-6 steel plates.
The 6T40 is a six-speed front-wheel-drive transaxle that makes its gears by applying two clutches at a time. The 4-5-6 clutch, as the name says, is one of the two clutches holding 4th, 5th and 6th. It pairs with the 1-2-3-4 clutch for 4th, with the 3-5-R clutch for 5th, and with the 2-6 clutch for 6th. The drum is the housing that holds that clutch pack: the steels lock into its outer lugs, the wave plate cushions the apply, and the pressure plate and snap ring set the stack height. When the lugs get notched, a spline breaks out, or the drum cracks, the pack cannot hold torque and the top three gears go with it.
The gear pattern is the giveaway. A 6T40 that loses reverse, 3rd and 5th together, usually with P0776, is pointing at the 3-5-R clutch, which is the most common failure in this family. A unit that loses 4th, 5th and 6th but still has reverse is pointing at the 4-5-6 side instead.
Start with a scan tool and the code history, then pull the pan and look at the magnet. Fine gray paste is normal wear; flat steel pieces are not. Our 6T40 common problems and fixes guide walks through the clutch-by-clutch failures and GM's own inspection order. Rule out the controls before you commit to teardown, because a sticking pressure control solenoid or valve body can also take out a range of gears; the 6T40 valve body symptoms guide covers what to check first. Once the unit is apart, inspect the drum lugs, the splines and the sealing surfaces with a light and a fingernail.
This assembly is listed for 6T40 units from 2008 on, and the same drum is listed for the 6T45 and 6T50. GM changed controls and some internal parts at the 2012 Gen 2 update, so do not assume every part of a Gen 1 and Gen 2 unit swaps. Before you order, count the outer lugs on your old drum (this one has 36), compare the overall shape and height, and check that the wave plate and pressure plate match what came out. If you are unsure, send us the year and VIN and we will help you check it. If your unit is a later Gen 2 build, also compare it with our 6T40 clutch drum for 2012-2021.
Clean the drum, check the bushing and sealing ring surfaces, and stack the new frictions and steels with the supplied wave plate and pressure plate in the factory order. Measure clutch clearance with the snap ring seated and correct it to spec before the drum goes back in. Air-check the pack on the bench. If the old drum shed metal, the valve body needs a full cleaning, and the cooler and lines need flushing. Compressing the 6T40 piston return springs safely takes the right tool; the DT-47799 clutch piston spring compressor set is built for this unit. A drum failure normally means new frictions and seals for the whole unit, so pair it with a 6T45 overhaul kit or the kit that matches your year. Refill with Dexron VI and set the level hot at the check plug, then clear adapts and let the TCM relearn.
| Fits | 6T40 2008 |
| Part type | Clutch Drum |
| Condition | New |
| Brand | OEM |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
The drum, a wave plate, a pressure plate and the snap ring. Frictions, steels and seals are not included, so plan on a rebuild or overhaul kit for those.
It is listed for 2008 and later 6T40, 6T45 and 6T50 units. Because GM made running changes at the 2012 Gen 2 update, compare the 36 outer lugs and the shape of your old drum before installing, or send us your year and VIN.
Look at which gears are missing. Losing reverse, 3rd and 5th together, usually with P0776, points at the 3-5-R clutch. Losing 4th, 5th and 6th while reverse still works points at the 4-5-6 side.
Dexron VI. GM lists a fluid change capacity of roughly 4.2 to 6.3 quarts for the 6T40, and the level must be set hot, around 185-203 F, at the level set plug rather than by a fixed fill amount.
Yes. After a teardown, clear the transmission adaptive values with a scan tool and drive the vehicle through its shifts so the TCM can relearn clutch fill times for the new pack.
