4L80E Master Rebuild Kit with Filter, Steels and Frictions

This is a master rebuild kit for the GM 4L80E heavy-duty 4-speed automatic, and it also covers the 4L85E. It is the kit you order when the unit is coming out of the truck for a full teardown: clutch frictions, steel plates, the seals and gaskets, a band, and a new oil filter so you are not bolting a fresh rebuild up to a filter that is holding the old unit's debris.

Fitment is the 1997-and-later 4L80E/4L85E found behind the 6.0L V8 in the Chevy Silverado 2500 HD, GMC Sierra 2500 HD, Chevy Suburban 2500, GMC Yukon XL 2500, and the Chevy Express 3500 and GMC Savana 3500 vans. These trucks tow and haul, and the typical reasons they end up on the bench are a slipping forward or direct clutch, a flare on the 2-3 shift under load, or burnt fluid after a hard towing season.

On the bench: tear the unit down, clean and inspect the hard parts (drums, planetaries, bushings, pump), then soak the new frictions in ATF before assembly and set clutch pack clearances as you stack each drum. Replace every seal and gasket in the kit rather than reusing the old ones, and install the new filter before the pan goes back on. Check the torque converter and flush the cooler and lines before the rebuilt unit goes back in, or contamination from the failure will find its way into the new clutches.