4T65E Transmission Master Rebuild Kit with Filter

This is the full soft-parts overhaul set for GM's 4T65E four-speed automatic transaxle, the front-wheel-drive unit that replaced the 4T60E and ran from 1997 all the way through 2011. It covers the H-body, W-body and U-body cars: Buick LeSabre, Park Avenue, Regal, Century, Rendezvous, LaCrosse, Allure, Terraza and Lucerne; Chevy Lumina, Monte Carlo, Impala, Venture and Uplander; Pontiac Grand Prix, Bonneville, Aztek, G6, Montana and Montana SV6; Oldsmobile Intrigue, Aurora and Silhouette; and the Saturn Relay, in 3.1L, 3.4L, 3.5L, 3.6L, 3.8L, supercharged 3.8L, 3.9L and 5.3L applications.

What is in the box: friction clutch plates, bonded apply pistons, Teflon and metal sealing rings, metal-clad (lip) seals, the case and channel plate gaskets, the full O-ring and rubber piston seal assortment, the pan filter, and the coast band. Steel plates are not included, which is normal for a master kit. Measure your existing steels for taper and heat discoloration on the bench; if they are flat and clean you reuse them, and if any are coned or blued you replace them separately before assembly.

These transaxles usually come apart for the same reasons. The forward and second clutch frictions cook and the car slips or flares on the 1-2 and 2-3 shifts, the rubber lip seals on the apply pistons harden and bleed off apply pressure so engagement goes soft and delayed, and the channel plate and case gaskets weep enough to drop line pressure. All of that is soft parts, and all of it is in this kit, so a unit that is mechanically sound inside can be brought back with one teardown instead of a replacement transaxle.

On the bench: pull the side cover and channel plate, air-check each clutch drum before you gut it so you know which circuits were leaking, then strip the drums and stack the new frictions in the same order and count you removed. Soak the new frictions in clean fluid before assembly. Set the coast band, replace every lip seal at the shafts and the axle seals, install the new filter, and torque the channel plate down in sequence. Air-check each drum again once it is stacked and before the cover goes on.