4T60E Input Drum, new and ready to install. Fits the 4T60E. Ships fast from the USA.
If you are rebuilding a 4T60E or 4T65E out of a Buick, Chevrolet, Oldsmobile or Pontiac front-wheel-drive car and found a cracked, warped or worn input clutch piston when you opened the input housing, this is the replacement. Read this first: although the listing is filed as an input drum, the part in the box is the input clutch piston, ACDelco (OE) GM part number 24203479, new in the original packaging. It is not a complete drum or housing. Our listing information shows it as a 1991-up service part for both the 4T60E and the 4T65E, and it is also listed for Volvo applications that used the same GM transaxle. Its aftermarket bonded interchange is 84964B.
On these GM transaxles the input shaft housing is the drum that carries two clutch packs, the input clutch and the 3rd clutch. Each pack has its own piston. The input clutch piston sits in the housing behind the input clutch plates; when apply oil arrives through the Teflon sealing rings on the housing and fills the cavity behind the piston, the piston pushes the plates together. When oil exhausts, the return springs pull it back and the pack releases. The piston carries lip seals on its inner and outer diameters, and those seals plus the flat, true face of the piston are what let the clutch hold torque without slipping. A piston that is distorted, cracked at the seal groove, or worn where the seal rides leaks apply oil, so the input clutch never clamps fully and the frictions start to burn.
Do the cheap checks first: correct fluid level checked hot, fluid condition and smell, and a code scan. Delayed engagement on these units also comes from the sealing rings on the input housing and the driven sprocket support they ride in, so read our 4T65E delayed engagement guide before pulling the transaxle. Once the input housing is apart, air-check the input clutch. Air bleeding past the piston rather than past the rings, a piston that will not lie flat on a surface plate, cracks around the seal groove, or a scored seal surface mean the piston should be replaced. For the bigger picture on what fails in this family, our 4T65E common problems guide covers the usual suspects.
GM 24203479 is listed for 1991-up 4T60E and 4T65E transaxles. Those units span many model years and several internal updates, so match before you install: compare the new piston side by side with your old one (outside diameter, inner hub diameter, and the shape of the apply face) and confirm the part number if yours is still legible. If you are unsure, send us your year, model and VIN before ordering and we will check it. It replaces the input clutch piston only; the 3rd clutch piston in the same housing is a different part. Browse other parts for this family on our 4T65E transmission parts page.
If the unit is coming apart anyway, a 4T60-E master rebuild kit for early units or a 4T65E master rebuild kit for 1997-2007 supplies the seals, frictions and steels to go with the new piston.
| Fits | 4T60E |
| Part type | Input Drum |
| Condition | New |
| Brand | GM |
| Reference | 24203479 |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. Despite the listing name, this is the input clutch piston only, GM 24203479, new in ACDelco packaging. You reuse your input housing, or buy a housing separately if yours is damaged.
It is listed for 1991-up 4T60E and 4T65E units. Compare it with your old piston before installing, and send us your year, model and VIN if you want us to check it first.
No. The input housing carries two pistons, one for the input clutch and one for the 3rd clutch. This part is the input clutch piston.
New piston lip seals, input clutch frictions and steels, and the solid Teflon sealing rings on the input housing. Most rebuilders do this as part of a full overhaul kit.
Fill with DEXRON-VI and check the level hot. Clear the shift adapts with a scan tool or by disconnecting the battery, then drive through a series of normal upshifts so the computer relearns.
