6T40E/6T45E rebuild kit with 15 frictions, 14 steels, 2 gaskets, a piston pack and filter for 2008-2011 Chevy Cruze and Buick Regal and LaCrosse.
If your 2008-2011 Chevrolet Cruze, Buick Regal, Buick LaCrosse or other GM front-drive car with the 6T40 or 6T45 six-speed is slipping in reverse, flaring into 3rd or 5th, or setting a clutch pressure code, the transaxle usually needs more than a fluid change. This kit puts the parts that wear out in one box: 15 friction plates, 14 steel plates, two gaskets, a bonded piston pack and a new filter. The piston pack is the part that separates it from a plain friction kit, and on this transmission it matters.
The 6T40 and 6T45 get six forward speeds from five clutch packs, named for the gears they apply in: 1-2-3-4, 3-5-R, 4-5-6, 2-6 and low/reverse, plus a low one-way clutch. Every shift is one clutch releasing while another applies, timed by the transmission control module from pressure control solenoids in the valve body. GM uses bonded pistons here, with the sealing lip molded onto the piston itself, so when a lip hardens or a piston cracks there is no separate seal to swap. You replace the piston. That is why ATRA rebuilders tell you to always put new bonded pistons in a 6T40 overhaul, and why a kit that already includes them saves a second order and a second teardown.
The steels matter as much as the frictions. Heat-blued or warped steels will glaze new frictions in a few hundred miles, so a kit with a full set of fresh steels lets you reset every pack to a known starting point instead of guessing which old plates are still flat.
Rule out the cheap things first. Check the fluid level at the correct hot temperature using the level set plug, because a low level on this unit causes the same delayed engagement that worn clutches do. Read the codes with a scan tool that shows TCM data, and note which gears slip. A slip in only one or two ranges with a pressure control solenoid code can be a valve body or solenoid problem, not the clutches. Our 6T40 common problems guide walks through the codes, and the 6T40 delayed engagement guide covers the fluid and solenoid checks. If you pull the pan and find clutch material and metal, the transaxle is coming apart and this kit is the right starting point.
This kit is listed for the GM 6T40E and 6T45E, including the 2011 Chevrolet Cruze 1.4L and 1.8L, the 2011 Buick Regal 2.0L and 2.4L, the Buick LaCrosse 2.4L and other 2008-2011 GM cars that use these transaxles. It carries reference 24230708. The 2008-2011 years are the first-generation units. GM changed the design for 2012, including a revised 4-5-6 clutch with a different friction count, so a 2012 or later car should be matched carefully before ordering. Check the transmission identification on the case and the RPO code on the glovebox or door label, or send us your year and VIN and we will confirm it. If you only need the filter for a later service, the 6T40/6T45 filter and pan gasket kit carries the same reference.
| Transmission | GM 6T40E / 6T45E 6-speed FWD |
| Reference | 24230708 |
| Includes | 15 friction plates, 14 steel plates, 2 gaskets, piston pack, filter |
| Listed fitment | 2008-2011 Chevy Cruze, Buick Regal, LaCrosse |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
It is listed for 2008-2011 6T40E and 6T45E applications, which are the first-generation units. GM revised the transaxle for 2012, including the 4-5-6 clutch, so a 2012 or later car needs to be matched by transmission code and VIN before you order. Send us the year and VIN and we will check it.
The 6T40 uses bonded pistons with the seal molded onto the piston, so a hardened lip or a cracked piston cannot be fixed with a separate seal. A cracked 1-2-3-4 piston is a known cause of upshift flare and P2723, and rebuilders replace all bonded pistons during an overhaul for that reason.
It gives you new frictions and steels for the 3-5-R pack, but inspect the waved plate and the drum splines carefully. If the waved plate is cracked or the drum splines are damaged, those parts must be replaced too, or the failure will come back.
Use DEXRON VI. A normal fluid change on the 6T40 takes about 4.2 to 6.3 quarts, and a rebuilt dry unit takes more, so have extra on hand. Set the final level at the level set plug with the fluid at 85-95 C.
Yes. Clear the transmission adaptive values after the rebuild so the control module relearns clutch fill on the new frictions and pistons. Without a reset the old learned values can cause harsh or soft shifts until they slowly correct.
