TH350 Planetary, used and ready to install. Fits the TH350. Ships fast from the USA.
This listing is the front planetary ring gear for a Turbo 350, the part GM calls the input ring gear. It is the heavy-duty one-piece design, a clean used core that has been run through an industrial hot-spray parts washer. Builders look for it when a TH350 in a Chevelle, Camaro, Nova, C10, Cutlass or Firebird has stripped the hub splines, chewed the ring gear teeth, or started whining in 1st and 2nd. Expect to press in a new bushing before it goes in, which is normal for any used ring gear.
The TH350 uses two planetary sets. The front set is made of this input ring gear, the output carrier and the sun gear. The forward clutch drives the ring gear in every forward gear, and its friction plates actually sit over the outside of this part: GM's assembly steps have you lower the forward and direct clutch assemblies into the case so the forward clutch faced plates are positioned over the input ring gear. Torque then goes from the ring gear teeth through the output carrier pinions to the output shaft. Because the ring gear is the input member of the front set and the forward clutch hub at the same time, a worn one can show up as either a gear problem or a forward clutch problem.
The one-piece heavy-duty style has the gear and hub made as a single unit, so there is no joint between them to loosen or crack under a big engine or a hard launch.
A TH350 has no transmission computer, so none of this sets a trouble code. You find it on a road test and at teardown.
Pull the pan first. Fine gray paste is normal; bronze flakes point to bushings and thrust washers, and steel chunks point to gears. Our TH350 filter and pan service guide shows what to look for. At teardown, inspect the ring gear teeth for chipped or pitted faces, check the hub splines for twist, and rock the gear on the output carrier. The front thrust washer between the forward clutch housing and ring gear should be checked for scoring too. If the problem is no Drive at all with good teeth, read the TH350 common problems guide first, because a forward clutch or pump fault is more common than a broken ring gear.
This is a TH350 and TH350C front input ring gear for the 1969-1986 Chevrolet, GMC, Pontiac, Oldsmobile and Buick family. GM made more than one ring gear design over those years, so compare the hub, spline count and tooth count to the one you removed before installing, or send us your year and VIN and we will help match it. It is a used part, cleaned and inspected, not new. More Turbo 350 hard parts are on the TH350 parts page, including the rear TH350 low/reverse planet.
Refill with Dexron ATF and confirm level hot on the dipstick.
| Fits | TH350 |
| Part type | Planetary |
| 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.
Front. It is the input ring gear, the outer gear of the front planetary set that the forward clutch drives. The rear low/reverse planet is a separate part.
The ring gear and its hub are a single piece instead of two pieces joined together, so there is no joint to loosen or crack under high torque.
Yes, plan on it. This is a used part and the bushing in the hub is a wear item. GM sets the new bushing .050 to .060 in. below the inner surface of the hub.
The TH350C lockup version uses the same front planetary layout. Compare the hub and spline count to your old ring gear, or send us the year and VIN to confirm.
The front thrust washer, the input ring gear to output carrier needle bearing if it is rough, the output carrier snap ring, and the forward clutch frictions if the hub was running off center.
Dexron automatic transmission fluid. Check the level hot on the dipstick after a test drive.
