TH350 Input Drum, remanufactured and ready to install. Fits the TH350. Ships fast from the USA.
Sometimes the input shaft in a Turbo 350 is perfectly good and it is the forward clutch housing around it that has given up: a crack at the hub, a scored piston bore, a lost check ball, or lug slots hammered out by a slipping pack. This listing is the TH350 and TH350C forward clutch drum by itself, supplied without the input shaft, for 1969-1986 transmissions in Chevrolet, GMC, Pontiac, Oldsmobile and Buick cars and light trucks. The industry interchange number on the listing is 35733D. It suits a rebuilder who wants to keep a known-good shaft, or a racer moving their old shaft or an aftermarket shaft into a sound housing. If you need the housing and shaft together, see the other forward drum listings linked below.
The TH350 input shaft is a press fit in this housing, so once assembled the drum turns at turbine speed any time the engine is running. The forward piston lives in a bore inside the drum. Line pressure from the pump cover crosses the two forward sealing rings on the pump hub, gets behind the piston and squeezes the forward clutch pack, which drives the input ring gear. That clutch is applied in every forward range and released in Park, Neutral and Reverse, so a leak anywhere in this housing shows up as a forward-only problem.
These overlap with the TH350's better-known faults, including worn pump hub rings and a leaking modulator, so prove where the pressure is going before you buy hard parts.
With the transmission apart, clean the old drum, set it on the pump hub and blow low-pressure air into the forward apply passage. A hiss at the piston lip says seals; a leak at the hub, the ball check or through a crack says housing. Inspect the lug slots and the piston bore under good light. If the unit is still in the car, start with the pressure checks in our TH350 delayed engagement guide, and use TH350 common problems and fixes to rule out the modulator and valve body first.
Listed for TH350 and TH350C transmissions from 1969 through 1986. GM produced the lockup TH350C from late 1979 through about 1984, and the forward housing family carries over, but shafts and small details can vary by application. Before ordering, compare your old housing with the photos, check the lug pattern and hub, and make sure the input shaft you plan to install fits this drum. If you are not sure, send us your year and VIN or a photo of your old drum and we will confirm it. Every TH350 part we carry is on our TH350 parts page.
A bare drum needs plates and seals, and the ATP SMS-9 TH350 master repair kit supplies frictions, steels, gaskets and seals in one box. If you would rather buy the drum and shaft as one assembly, the 1980-1986 TH350 forward housing with input shaft is the matching piece.
| Fits | TH350 |
| Part type | Input Drum |
| Condition | Remanufactured |
| 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.
No. It is the forward clutch drum only, supplied without the input shaft. You reuse your old shaft or install a new one with a press. If you want both together, look at our TH350 forward housing listings that include the shaft.
It is listed for TH350 and TH350C from 1969 through 1986. Compare the hub, lug pattern and your input shaft with this drum, or send us your year and VIN and we will confirm before it ships.
No. Plan on a forward clutch pack and new piston seals, which come in a TH350 master rebuild kit.
Support the shaft and measure runout at the rear thrust washer surface. GM allows no more than .005 inch.
GM lists .011 to .082 inch, adjusted with one of the selective pressure plates.
DEXRON automatic transmission fluid. Check the level hot after cycling through the gears.
