TH350 Overhaul Kit, new and ready to install. Fits the TH350. Ships fast from the USA.
If you are rebuilding a Turbo 350 and do not want to sort out whether yours is an early non-lockup unit or a later TH350C, this kit takes the guesswork out. It is listed for every TH350 and TH350C from 1969 through 1986, built for both non-lockup and lockup torque converter applications. It reseals the transmission inside and out: valve body, pump and filter gaskets, a full sealing ring set, the cork-rubber pan gasket, piston lip seals, O-rings and the metal-clad external seals. It is a soft-parts kit only, with no friction plates, steels, band or bushings.
Every shift in a TH350 is oil pressure acting on a piston. Lip seals hold that pressure behind the forward, direct and low/reverse clutch pistons, and sealing rings carry the oil across the spinning parts. The gaskets keep circuits separated between the case, spacer plate and valve body. When one of those leaks, the clutch it feeds fills slowly and slips under load. The washer seals under the pump bolts and the pump O-ring matter too; GM lists both as front-of-transmission leak points, along with the front seal itself.
Check the fluid first. Burnt, black fluid or friction material in the pan means the clutches are done and the job is a full rebuild, not just a reseal. If the fluid is clean but engagements are slow, run through the pressure and pump checks in our TH350 pump failure guide, because a worn pump bushing will out-run any new seal. For leaks, our TH350 fluid leak guide covers each joint and its factory torque.
Listed for all 1969-1986 TH350 and TH350C transmissions in Chevrolet, GMC, Pontiac, Oldsmobile and Buick cars and light trucks. The second valve body gasket is there because spacer plates changed over the years; lay each gasket over your plate and use the one whose holes line up exactly. If you only have a 1969-1980 non-lockup unit, the 1969-1980 TH350 overhaul kit is another option. Not sure what you have? Send us the year and VIN, or browse the TH350 collection.
Pre-lube every lip seal in ATF, install the sealing rings with assembly gel, and air-check each clutch circuit before closing the case. Drive the metal-clad front and rear seals in square with a proper installer, and look at the converter hub and driveshaft yoke for grooves before you reuse them. The pump bolts take 18-1/2 lb-ft and the extension housing 25 lb-ft per GM's 1976 truck supplement. The filter is not in this kit; pair it with a new filter and refill with Dexron VI. A stock-pan refill after a drain is about 2-1/2 quarts, but a dry rebuild takes far more, so finish on the dipstick.
Planning a full rebuild rather than a reseal? Add a TH350 clutch module for the frictions, and a TH350 shift kit if you want firmer shifts while the valve body is apart.
| Fits | TH350 |
| Part type | Overhaul Kit |
| Condition | New |
| 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.
Yes. It is listed for all TH350 and TH350C units from 1969 to 1986, with both non-lockup and lockup torque converters.
Spacer plates changed over the production run. Lay each gasket over your plate and use the one whose holes line up exactly.
No. The kit includes the filter gasket but not the filter. Buy a 1969-1986 TH350 filter to install with it.
Only if the slip comes from leaking seals. If the clutches are burnt, you also need frictions and steels, and a worn pump or valve body bore must be repaired too.
About 2-1/2 quarts refills a stock pan after a drain, but a dry unit and converter take much more. Add fluid in steps and set the final level on the dipstick, engine running and hot.
