6L45 6L50 6L45E 6L50E Transmission Overhaul Rebuild Kit

This is the TRANSPEED overhaul (reseal) kit, part number T20102A, for the GM 6L45 and 6L50 rear-wheel-drive six-speed automatics, including the 6L45E and 6L50E variants. This is the transmission GM shared out to the rear-drive Cadillacs and to BMW, so one kit covers the Cadillac CTS, STS and SRX with the 3.6L and the 4.4L/4.6L V8 (roughly 2007-2013) as well as the BMW 128i, 328i/328xi and X3/X5/X6 3.0L cars of the same era. It is the kit you open when you drop the pan to fix a leak, chase delayed engagement, or reseal the unit during a clutch job.

Inside is the full overhaul gasket and seal set: every internal rubber-coated and metal-clad seal, the O-rings, the pan and case gaskets, and the Teflon and cast-iron sealing rings that ride on the drums and shafts. Hardened, shrunken seals are the number-one cause of low line pressure on these units, and low pressure is what shows up at the wheels as a soft 1-2, a slipping upshift, or converter clutch shudder that comes and goes with fluid temperature. Replacing the seal package as a set restores clamp on the clutch packs and gets the pressure back where the valve body expects it.

Use it on a bench teardown: as you split the drums and pull the pistons, replace every seal and sealing ring this kit supplies rather than reusing a single tired ring, then reset your clearances before final assembly. Note this is a reseal/overhaul kit, so it does not include friction plates, steels, or hard parts; pair it with a friction and steel set if your clutches are worn. Fits the 6L45, 6L50, 6L45E and 6L50E. Ships from the USA; handling in 1-2 business days.