TH350 Input Drum 1980-1986, used and ready to install. Fits the TH350. Ships fast from the USA.
A rebuild that turns up a cracked forward drum, a chewed-up input shaft spline or ring lands worn into steps does not need a whole used transmission to fix it. This is a used, bare forward clutch housing with the input shaft for 1980-1986 TH350 and TH350C transmissions, used in Chevrolet, GMC, Pontiac, Oldsmobile and Buick cars and light trucks during the years the lockup version was in production. It is sold as the hard part only, as pictured: the housing and the shaft, ready for your own piston, seals and clutch plates. That makes it the right buy when your plates are fine but the drum or shaft is not, or when you are building a unit from a bare core.
The input shaft takes power from the converter turbine, and since it is pressed into this housing, the housing spins at engine-driven turbine speed every second the engine is running. Inside, the forward piston sits in a bore in the housing. Pump-cover fluid crosses two rings on the pump hub, fills the piston cavity and clamps the clutch pack, which then drives the input ring gear. The forward clutch is on in first, second and third and off in Neutral, Park and Reverse.
With the unit on the bench, clean the old housing and set the housing on the pump hub and air-check the forward circuit. A hiss from the piston means seals, a hiss at the hub or the ring lands means wear, and either one tells you whether you need new soft parts or a new hard part. Put the shaft in V-blocks and check it at the rear thrust washer surface; GM's limit is .005 inch runout. If you have not opened the transmission yet, our TH350 delayed engagement guide shows the pressure checks to run first, and TH350 pump failure symptoms helps you rule out a worn pump that only looks like a forward clutch problem.
This listing is for 1980-1986 TH350 transmissions. The TH350C lockup version, made from late 1979 through about 1984, carries GM codes MV4, MX2, MX3 and MX5 and has an electrical connector on the left side of the case, while a non-lockup TH350 uses M33, M38 or M39. Since this year range can include either version, compare the input shaft from your old housing with this one: overall length, the front spline and the ring land layout should match. Send us your year and VIN or a photo of your old shaft and we will confirm the match before it ships. Every TH350 part we stock is listed on our TH350 parts page.
A bare housing needs plates and seals, and the TH350 master repair kit covers the frictions, steels, gaskets and seals. If the direct pack in front of it is tired, the loaded TH350 direct clutch drum goes in at the same time.
| Fits | TH350 1980-1986 |
| Part type | Input 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.
No. It is a used, bare forward clutch housing with the input shaft, as pictured. Plan on new piston seals and a clutch pack, which come in a master rebuild kit.
It is listed for 1980-1986, which overlaps the TH350C years. Compare your old input shaft length, spline and ring lands with this one, or send us your year and VIN.
Set the housing on the pump hub and air-check the forward circuit. Leaks at the piston are seals; leaks at the hub or worn ring lands, cracks, or a loose ball check mean the housing or shaft should be replaced.
GM allows no more than .005 inch measured at the rear thrust washer surface.
DEXRON automatic transmission fluid. Check the level hot on the dipstick after cycling through the gears.
