TH400 Clutch Drum 1964-98, used and ready to install. Fits the TH400. Ships fast from the USA.
If your Turbo 400 shifts 1-2 cleanly but slips or flares going into third, or Reverse is soft and getting worse, the direct clutch drum is one of the first hard parts a rebuilder looks at. This is a used, original GM direct clutch drum for the TH400 and the lighter-duty TH375, listed for 1964 through 1998 Chevrolet, Buick, Oldsmobile, Pontiac and GMC applications. It comes with the lug-style intermediate outer race, the roller and spring assembly, the retainer and the snap ring. The housing has no check ball, the drive lugs show slight wear, and the sealing ring area is in good condition.
GM's service manual calls this part the direct clutch housing. Inside it sits the direct clutch piston, its release springs and a five-friction pack held in by a backing plate and snap ring. When the valve body sends oil to it, the direct clutch locks up for third gear and for Reverse. On the outside, the hub carries the intermediate roller clutch, which holds during second gear, and the front band wraps the outer surface for manual-second engine braking. That means one housing has to hold apply pressure, drive the steel plates on its lugs and give the band a clean surface. Worn lug slots, a cracked hub or a leaking piston bore all show up as slip in the gears this drum serves.
The 1975 GM manual lists a damaged or missing check ball, cracked piston, bad seals and a backwards-installed intermediate roller clutch among the causes of burned direct clutch plates. Sonnax also notes that hard-launched TH400s can break the low roller clutch, and the debris from that failure often takes out the direct drum, so a high-horsepower unit deserves a look at both.
Run a line pressure check first, because a weak pump starves every clutch and can look like a drum problem. If pressure is in range but third and Reverse both slip, the direct circuit is the suspect. With the unit apart, air-check the direct piston, look for cracks around the lug slots and hub, and inspect the roller cam and outer race for scoring. Our TH400 common problems and fixes guide covers the direct drum and roller clutch failures, and if engagement is slow in every range, start with the TH400 delayed engagement guide instead.
This drum is listed for the TH400 and TH375 from 1964 through 1998 across Chevrolet and Buick-Olds-Pontiac cars and trucks. GM changed direct housings and pistons over that span, and the key detail here is that this housing has no check ball. The 1975 manual notes that the service replacement direct piston carries its own check ball, so pair this housing with a piston that has one. Compare hub height, bushing bore and lug count with the drum you are pulling, or send us your year and VIN before ordering. You can also see our other TH400 clutch drum for 1964-1990 and the full TH400 parts collection.
Clean the housing and blow out every feed passage before assembly, then check the bushing and the sealing ring lands on the center support for wear. Fit new inner, outer and center piston seals, install the release springs, and stack the frictions and steels in the order your manual calls for your model code, ending at the backing plate. Install the roller assembly so the drum freewheels in the correct direction; if it is in backwards, the direct clutch will burn. Air-check the piston, then fill with Dexron-type ATF. Most rebuilders put this drum in with new frictions and seals, for example the TH400 performance master kit 1965-1996 with its friction and steel modules, or the TH400 filter and pan gasket set for the final service.
| Fits | TH400 1964-98 |
| Part type | Clutch Drum |
| Condition | Used |
| 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.
It is the direct clutch drum, the housing that carries the intermediate roller clutch on its hub and the direct clutch pack inside. The forward drum is the one with the turbine shaft through it.
No, as long as the direct piston you install has a check ball. GM's 1975 service manual notes that the service replacement direct piston carries its own check ball. Match your piston to the housing before assembly.
The drum ships with the lug-style intermediate outer race, the roller and spring assembly, the retainer and the snap ring. Frictions, steels, piston and seals are not included.
Yes, it is listed for both the TH400 and the TH375. Compare it with your old drum, because the plate count can differ by model code.
The TH400 takes Dexron-type automatic transmission fluid. A current Dexron III or compatible full-synthetic is the usual choice.
