6T40 Master Rebuild Kit 2008-11, new other (see details) and ready to install. Fits the 6T40. Ships fast from the USA.
If you are rebuilding the six-speed out of a 2008-2011 Chevrolet Malibu, an early Cruze or another GM front-driver with the 6T40, you are working on a first-generation unit, and the parts and the failure history are not the same as the later trucks and cars. This kit is listed for 2008-2011 6T40 transmissions. The photo shows the reseal side of an overhaul: the pan and case gaskets, the valve body gasket set, lip seals, sealing rings, a filter and a set of bushings. It is the job you do when the unit is slipping, leaking from several places, or has come apart after a 3-5-reverse failure and needs to be sealed up right.
Every clutch in the 6T40 is applied by oil fed through the case, the drum sealing rings and the piston seals, and controlled by the TEHCM bolted inside the case. On an early unit those seals have been through a lot of heat cycles, and a hardened lip or a worn ring lets apply pressure bleed off, which the TCM sees as slip and answers with harsher, longer shifts until a ratio code sets. Replacing every seal, ring, gasket and the filter at once restores the hydraulic side of the transmission so the clutches get full pressure again. The bushings matter as much: a worn bushing lets a shaft or drum wobble and chews through the sealing rings that ride next to it.
Check the level first with the fluid hot, since both underfill and overfill change how this unit shifts. Then scan for codes and pull the pan. Clean fluid with a single solenoid or pressure switch code points to the TEHCM side of the job rather than a rebuild. Fine steel slivers and pieces of a wave plate mean the 3-5-R clutch has failed and the case has to come apart. Our 6T40 common problems and fixes guide runs through those checks in order, and the 6T40 rebuild cost guide shows which hard parts tend to get added once it is open.
The listing covers 6T40 transmissions built for 2008 through 2011. Those are Gen 1 units; GM rolled out the Gen 2 changes, including a revised 4-5-6 clutch and the removal of the TEHCM pressure switches, starting in 2012, so a 2012 or later case is not a safe match. Model years overlap at the changeover and some GM vehicles in this range used the heavier 6T45 instead, so read the transmission ID tag and lay your old gaskets beside the new ones before you start, or send us your year and VIN and we will check it. For a 2012 unit use the 2012 6T40 master rebuild kit, and every other kit for this family is on the rebuild kit category page.
Frictions and steels are not shown in the photo for this kit. If your clutch packs are burnt or worn, order plates with the 6T40E/6T45E master rebuild kit with frictions or confirm the contents with us before you tear down. On any 2008-2011 unit, GM recommends replacing the 3-5-R piston and waved plate during the overhaul, and Sonnax warns that a broken plate often damages the drum splines, so inspect that housing carefully. ATRA advises against reusing the bonded pistons. Drive in the new bushings square, size-check the drum sealing rings, and use the 6T40 pump seal installer set so the new seals seat without a cut lip. Fill with Dexron VI, set the level hot at the check plug, and run the adaptive learn with a scan tool before you judge the shifts.
| Fits | 6T40 2008-11 |
| Part type | Master Rebuild Kit |
| Condition | New Other (See Details) |
| 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.
It is listed for 2008-2011 units. GM's Gen 2 update began in 2012 and changed the 4-5-6 clutch, the TEHCM and the seal ring layout, so a 2012 or newer unit needs the 2012 kit. Send us your year and VIN if you are not sure.
The photo shows gaskets, seals, sealing rings, a filter and bushings, but no clutch plates. If your packs are burnt or worn, pair it with a kit that includes frictions or ask us to confirm the contents first.
Replace the 3-5-R piston and waved plate, as GM recommends for these years, and check the 3-5-R drum splines for damage. Do not reuse the bonded pistons, and inspect the low one-way clutch.
On 2008-2011 units no reverse with P0776 is usually the broken 3-5-R waved plate, which means the unit has to come apart. Check the fluid level and the pan magnet first; heavy metal confirms it.
Dexron VI only. Set the final level with the fluid hot, around 85-95 C, through the check plug, then run the transmission adaptive learn with a scan tool.
