TH350 Planetary 1969-86, used and ready to install. Fits the TH350. Ships fast from the USA.
If your Turbo 350 howls at cruise, lost first or reverse, or left bright metal and chewed bronze in the pan, a planetary carrier is one of the parts you will be pulling out of the case. This is a used GM planetary carrier for the 1969-86 TH350, the three-speed automatic GM bolted behind Chevrolet, GMC, Pontiac, Oldsmobile and Buick cars and light trucks for almost two decades. It is a lower-cost way to replace one damaged gearset during a rebuild without buying a complete hard-parts kit.
GM describes the TH350 as a converter driving two planetary gear sets, with four multiple-disc clutches, two roller clutches and an intermediate overrun band deciding which member of each set is driven or held. In the 1975 Buick manual the front set is the output carrier, driven through the input ring gear and snapped to the output shaft. The rear set is the reaction carrier, which rides inside the output ring gear and is held by the low and reverse clutch and roller clutch for first and reverse. A long sun gear and drive shell ties the two sets together. Because every gear the transmission makes runs through these pinions, a carrier with loose pins or worn pinion bearings shows up in more than one range.
Plenty of TH350 complaints are not gear problems at all. A soft 1-2, no second gear or a slow engagement usually traces back to the intermediate sprag, worn valve body bores or a leaking modulator, which our TH350 common problems guide walks through.
A planetary noise follows vehicle speed and is often loudest in first and reverse where the gearsets are working hardest. Pull the pan and look at the debris: fine clutch material points to slipping packs, while needle rollers and brass-colored washer material point to the gear train. Once the unit is apart, spin each pinion and rock it side to side; any roughness, blue heat marks or chipped teeth mean the carrier is done. If you are not sure whether the noise is the pump or the gearset, the TH350 pump failure guide covers how a pump whine differs from a gear whine.
The listing covers the TH350 from 1969 through 1986, including the later TH350C lockup version, since the gear train did not change for lockup. The TH350 has two different carriers, the output carrier in front and the reaction carrier at the rear, and they are not interchangeable. This is a single used carrier. Set your old part next to the photo and match the pinion count, the hub splines and the outer teeth before you order. The TH350 also had heavy-duty and Buick 375B variants. If you are not certain which carrier you need, send us your year, vehicle and a photo of the old part and we will check it. Every other TH350 part we stock is on the TH350 parts page.
A failed gearset rarely fails alone, so most buyers do the job with a TH350 master rebuild kit or at least new frictions from a TH350 clutch module. Flush or replace the cooler and lines so metal from the old carrier does not get pumped back through the new bushings.
| Fits | TH350 1969-86 |
| Part type | Planetary |
| 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.
This is one used carrier, and the TH350 uses two different ones: the output carrier in front and the reaction carrier in the rear. Compare the photo with your old carrier (pinion count, hub splines, outer teeth). If you want us to confirm it first, send a photo of your part and your year and vehicle.
Yes. The TH350C is a TH350 with a lockup converter circuit. The gearsets are the same family, so this listing covers 1969-86 including the C version. The Buick 375B and heavy-duty builds can use different parts, so check before you order.
Replace the thrust bearings and washers on both sides of the gearset and the snap rings GM says to use new. Inspect the reaction carrier and input ring gear bushings too. If metal went through the transmission, plan on a rebuild kit, new frictions, a new filter and a flushed or replaced cooler.
Gear noise changes with road speed and is usually worst in first and reverse. Pump whine follows engine rpm, even in Park or Neutral. Needle rollers or bronze washer material in the pan also point to the gear train.
Dexron ATF. After a rebuild, fill it, start the engine, run the selector through the ranges, then set the final level with the fluid hot on the dipstick.
No. The TH350 is fully hydraulic, with shifts controlled by the governor and modulator, so there is nothing to relearn. Road test it and check for leaks and noise.
