4T40E Clutch Drum, used and ready to install. Fits the 4T40E. Ships fast from the USA.
If a Chevrolet Cavalier, Malibu, Cobalt or HHR, a Pontiac Sunfire, Grand Am or G6, an Oldsmobile Alero or a Saturn Ion slips in Drive, takes a long time to engage forward, or still slips after the clutches were replaced, the forward clutch drum belongs on the suspect list. This is a used GM forward clutch drum for the 4T40E and 4T45E four-speed transaxle, the bare drum (housing) that the forward clutch pack and its pistons live in. Rebuilder catalogs list a single forward clutch drum for 1995-up units, and this one was pulled from that family.
The forward clutch is the pack that puts the transaxle in gear when you select Drive, and the drum is its housing. It rides on the forward drum support at the back of the case on two bushings, a small one in front and a larger one at the rear, and it takes its apply oil through two Teflon sealing rings on that support. Inside are a bonded inner and outer piston, a return spring and retainer, seven .069 in. frictions with seven matching steels, a thin waved steel to cushion the apply, and a .122 in. pressure plate held by a snap ring. A plastic three-tab washer separates the forward hub from the drum, and a thrust bearing sits between the drum and its support.
Because the oil travels across the support rings, through the drum and under a bonded rubber piston lip, there are several places for pressure to escape. Any leak there shows up as a forward slip, and Reverse, which has its own clutch, often still works.
Many burned forward packs in this unit start in the pump, not the drum. TransGo's 4T40E/4T45E pressure regulator kit description blames wear in the pressure regulator valve bore for most of what goes wrong with this transaxle, listing burned forward or reverse frictions, TCC codes P0741 and P0742, planet burn-up and overheated fluid. Before you buy hard parts, check the fluid level and condition, scan for codes, and run line pressure in Drive and Reverse with our transmission pressure testing guide. The slipping diagnosis guide helps separate a hydraulic loss from a worn clutch. On the bench, check the drum bushings, the bore where the support rings seal, the friction lug slots for notching, and look for cracks around the piston cavity and snap ring groove.
This drum is for the GM 4T40E and 4T45E transaxle built from 1995. The 4T40E was used in the 1995-2005 Cavalier and Sunfire, 1997-2003 Malibu, 1999-2004 Alero, 1999-2005 Grand Am and Saturn L-Series; the higher-capacity 4T45E went into the Cobalt, HHR, G5, G6, Ion and later Malibu and Grand Am models. GM made changes inside the family over the years, including different forward drum supports, so compare your old drum with this one before installing: bushing sizes, the spline and lug pattern for the clutch plates, the snap ring grooves and the overall height. If you are not sure, send your year and VIN and we will check it. Every part we carry for this unit is on the 4T40E parts page.
If your reverse input drum or input sprag is also worn, our 4T40E reverse input drum is the matching hard part.
| Fits | 4T40E |
| Part type | Clutch Drum |
| Condition | Used |
| Brand | OEM |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
It is the forward clutch drum, the housing for the seven-plate forward pack. The 4T40E also has a reverse input drum that carries the reverse clutch and the input sprag; that is a different part, listed separately in our 4T40E collection.
It is listed for both. GM revised parts inside the family, so compare bushing sizes, the clutch spline pattern, snap ring grooves and height against your old drum, or send us your year and VIN before ordering.
A forward-only problem points at the forward clutch circuit, which includes this drum, its pistons, the support sealing rings and the line pressure feeding them. Run a line pressure test first; low pressure in every range points to the pump or regulator rather than the drum.
New forward frictions and steels, both forward pistons, the two Teflon support rings, drum bushings if worn, and a filter. Most builders install a master rebuild kit at the same time.
Dexron VI. GM states Dexron VI is backward compatible with units that originally specified earlier Dexron fluids.
