6T40E Transmission Master Rebuild Kit for GM FWD Cars

A master overhaul kit for the GM 6T40E/6T45E front-wheel-drive six-speed. It is built for a full teardown of the unit, replacing the wear parts that go bad in these transmissions so you are not ordering seals and clutch components separately.

The listed fitment is the 2011 Chevrolet Cruze (1.4L turbo and 1.8L), Buick Regal CXL (2.0L turbo and 2.4L) and Buick LaCrosse CX/CXL 2.4L. The 6T40E and 6T45E share the same basic architecture and were used across many GM compacts and midsize cars, but GM made running changes over the years, so match your case and clutch stack against what comes out of the unit before you commit.

Typical 6T40 failures that lead to a rebuild are a slipping or burned 3-5-R clutch, the known wave-plate breakage in the 3-5-R pack, harsh 1-2 and 2-3 shifts, and a delayed reverse from worn piston seals. When the unit is apart, inspect the 3-5-R wave plate and the valve body bores; replacing frictions without addressing a cracked wave plate or worn bores will bring the same complaint back.

Use Dexron VI for the refill and follow the service manual for clutch clearances. Run a TCM relearn after installation so shift adapts start from a clean baseline.