4T40E Master Rebuild Kit, new and ready to install. Fits the 4T40E. Ships fast from the USA.
When a 4T40E in a Chevrolet Cavalier, Malibu, Cobalt or HHR, a Pontiac Sunfire, Grand Am or G5, an Oldsmobile Alero or a Saturn L-Series starts slipping between gears, flares on the 2-3 shift, or comes out of the pan with burnt fluid and clutch material on the magnet, the fix is usually a full overhaul rather than one part. This new master rebuild kit for the 1995-up 4T40E is built for exactly that job. It contains Borg-Warner friction clutches with matching steel plates, a Transtec soft parts kit with every rubber seal and gasket, both bands, a new filter, and the molded rubber bonded piston kit, so the unit comes back together with every wear item renewed at once.
The 4T40E is GM's small four-speed front-drive transaxle. Power comes off the torque converter through a drive chain to the input side, and the gear ratios come from multiple-disc clutches, one-way clutches and two bands. Each clutch pack is applied by a rubber-lipped piston, and the bands are applied by servos. Over time the friction material glazes or burns, the steels heat-discolor and warp, and the piston lips and sealing rings harden and leak apply pressure. Low apply pressure lets a clutch slip, slipping makes heat, and heat finishes off the rest of the pack. That is why this kit includes steels: reusing tired steels with new frictions is a common reason a fresh rebuild slips again. The bonded pistons replace the separate lip seals with rubber molded onto the piston, which removes a frequent leak point during assembly.
Check the fluid level hot and smell the fluid first. Rule out electrical faults by scanning for shift solenoid and pressure control codes, because a sticking pressure control solenoid can make a healthy unit feel like it is slipping. A line pressure test is the best way to separate a pressure problem from worn clutches, and our transmission pressure testing guide shows how. If the clutches are clearly burnt, read our rebuild versus replacement cost breakdown to decide whether a bench rebuild makes sense for your vehicle.
This kit is listed for the 4T40E from 1995 up. The same family also includes the 4T45E, which many vehicles used instead, including the Saturn Vue and Ion and V6 versions of the Alero and Grand Am, and kit suppliers commonly list 1995-2007 and 2008-up units separately. Count your clutch plates and compare the bands and filter with what comes out of your unit before you start assembly, and if you are unsure whether you have a 4T40E or 4T45E, send us the year, model and VIN and we will check it. See every part we carry for this unit on the 4T40E parts page.
Soak every friction plate in clean transmission fluid for at least thirty minutes before installation. Inspect the drums, the input sprag, the reaction sun shell and all bushings for wear before reassembly; a cracked or worn 4T40E reaction shell or a slipping 4T40E sprag clutch will undo a new kit. Set each clutch pack clearance to specification, check the drive chain for stretch, and replace or flush the torque converter, since debris trapped in the old converter will contaminate the new clutches. Because valve body bore wear is a known 4T40E problem, inspecting the valve body or adding the 4T40E shift kit while the unit is apart is cheap insurance. Refill with Dexron VI ATF, check the level hot, and perform the adaptive relearn described in our relearn after a rebuild guide so the computer learns the new clutch apply times.
| Fits | 4T40E |
| Part type | Master Rebuild Kit |
| Condition | New |
| Brand | GM |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
Yes. This master kit includes Borg-Warner frictions with steel plates, plus the seal and gasket set, both bands, a filter and the molded rubber bonded piston kit.
The kit is listed for the 1995-up 4T40E. The 4T45E is the same family, but parts lists can differ, so compare plate counts and bands with your old parts or send us your year, model and VIN before ordering.
Inspect the sprag, reaction shell, drums and bushings, check the drive chain, and service or replace the torque converter. Many builders also repair the pressure regulator bore or install a shift kit while the valve body is out.
Use Dexron VI automatic transmission fluid. It is backward compatible with the earlier Dexron III specification used when these units were new.
Yes. Clear the adaptive shift values with a scan tool and drive the vehicle through a full relearn cycle so the computer learns the new clutch apply times. Skipping it often causes harsh or slipping shifts on a fresh rebuild.
