4L60E Heavy Duty Stage 3 Rebuild Kit with 3-4 PowerPack

This is a full teardown kit for the GM 4L60E, the four-speed overdrive automatic that sits behind almost every small-block GM truck, van and F-body built from 1997 through 2003. It ships with the friction plates, steel plates, brake band, deep-pan filter, pan gasket, O-rings and metal-clad oil seals needed to close the case in one pass, plus the heavy-duty 3-4 PowerPack clutch pack. Manufacturer part reference is 4L60E Transmission Rebuild; the same internals cover the 4L65E.

The 3-4 clutch pack is why this kit exists. In a stock 4L60E the 3-4 pack carries load in both third and fourth, and it is almost always the first thing to burn - you pull the pan, find the fluid brown and the filter loaded with friction material, and the truck has started slipping or flaring on the 2-3 and 3-4 shifts. A PowerPack adds friction surface to that clutch pack so it holds more torque than the factory stack, which is the reason people step up to it on a truck that tows, on an LS swap, or on any build that made more power than the transmission left the factory expecting.

Confirmed fitment covers 1999-2003 Cadillac Escalade, 2002-2003 Escalade EXT and 2003 Escalade ESV; 1997-1999 GMC C1500 and C1500 Suburban, 2002-2003 Envoy and Envoy XL, 1997-2003 Jimmy, Safari, Savana 1500 and Sonoma, and 1999-2003 Sierra 1500; 1997-2003 Chevy Astro, Blazer, Express 1500, S10, Suburban 1500 and Tahoe, 1999-2003 Silverado 1500, 2002-2003 Trailblazer and Trailblazer EXT, 1997-2001 C1500, 1997-1999 C1500 Suburban and Silverado, and 1997-2002 Camaro; plus 1997-2002 Pontiac Firebird. The 4L60E changed from a one-piece to a removable bellhousing in 1998 and the input shaft spline count differs across the range, so check the case and the tag before ordering.

Order of work on the bench is the usual one: pull the pan and valve body, split the case, strip each drum, measure the drums and the band contact surface while everything is apart, then soak the new frictions in ATF before they go in. Set clutch clearance with the selective plates as you stack each pack rather than assuming the kit lands you in spec, and check end play with a dial indicator before the pump goes back down. Kit ships at 10.78 lb in a 16.5 x 12.5 x 7 in box.