TH350 Overhaul Kit 1996-86, new and ready to install. Fits the TH350. Ships fast from the USA.
A Turbo 350 that drips from the bell housing, takes a second or two to grab Drive on a cold morning, or has gone soft on the 1-2 shift usually has nothing exotic wrong with it. Fifty-year-old rubber and worn sealing rings let oil escape before it ever reaches a clutch piston. This is the Alto overhaul kit for the GM Turbo Hydra-Matic 350, catalogued for the non-lockup TH350 from 1969 to 1979 and the lockup TH350C from 1980 to 1986. Those units sit behind small-block and inline engines in Chevrolet, GMC, Pontiac, Oldsmobile and Buick cars and light trucks, from Novas and Camaros to C10 pickups. Note that the year range in the listing title is a typo for 1969-1986; there is no 1996 TH350.
It is the parts for one rebuild of the sealing side only. Friction plates, steels, the intermediate band, bushings and a filter are not included.
The TH350 is a fully hydraulic three-speed. A gear-type front pump makes line pressure, the valve body routes it, and four clutch packs plus one band do the work. Oil for the forward and direct clutches leaves the stationary pump hub and crosses into spinning drums over sealing rings; GM's 1975 chassis manual shows three rings feeding the direct clutch and two feeding the forward clutch on that hub. Each piston then holds apply pressure with lip seals. When those rings wear their grooves or the rubber hardens, oil bleeds back into the sump, fill time gets longer, and clamping force drops. Renewing every one of them is what brings engagement and shift feel back after the hard parts are inspected.
Start with fluid level and condition. Dark, burnt fluid with friction material in the pan means the clutch packs need replacing too, so budget for plates along with this kit. If the complaint is a slow engagement, note which range is late: Drive only points at the forward circuit, Reverse only points at the direct and low/reverse circuits. Our TH350 delayed engagement guide walks through that pattern and the line pressure check, and the TH350 fluid leak guide lists GM's factory leak points so you do not tear down a unit for a filler tube O-ring.
The kit is listed for the GM TH350 from 1969 through 1979 and the TH350C from 1980 through 1986. The C version adds a torque converter clutch with an electrical connector on the left side of the case, and pump and valve body details changed across the run, so lay the new gaskets over your old ones and match the bolt and passage holes before the kit is opened. Opened soft-parts kits are usually not returnable. If you are unsure whether you have a 350 or a lockup 350C, send us the year, vehicle and VIN and we will check it for you. You can see everything we stock for this unit on the TH350 parts page.
| Fits | TH350 1996-86 |
| Part type | Overhaul Kit |
| Condition | New |
| Brand | Alto |
| 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 gasket and seal kit: paper gaskets, O-rings, lip seals, metal-clad seals, sealing rings and a pan gasket. Friction plates, steels, the band, bushings and the filter are bought separately based on what your teardown shows.
Yes. The kit is catalogued for the TH350 from 1969 to 1979 and the TH350C from 1980 to 1986. Compare the new gaskets against your old ones before installing, and send us your year and VIN if you are not sure which version you have.
That is a typo in the year range. The TH350 family ended in 1986, and this kit covers 1969 through 1986.
GM specified Dexron automatic transmission fluid for the TH350. A current Dexron VI fluid is the common replacement. A stock pan takes roughly 2-1/2 quarts after a drain, but a rebuilt unit with a dry converter needs much more, so fill gradually and set the level by the dipstick at operating temperature.
Sometimes. Check fluid level, the modulator for a ruptured diaphragm, and line pressure first. If pressure is good and the fluid is clean, a leak at a piston seal or sealing ring is likely, and that means the unit has to come apart to install this kit.
