TH350 Master Rebuild Kit 1969

Restoring a numbers-era Chevelle, Camaro, Nova, GTO or C10 and want the Turbo 350 overhauled with a kit that came out of the same decade? This is a new old stock Windsor Products master rebuilding kit, number 38000, still in its original sealed box. The label reads Turbo-Hydra S.T. "350" 1969-UP, and the kit carries the gaskets, seals, friction plates and steel plates for a full TH350 overhaul. It suits a builder chasing slipping, burnt fluid and seeping seals on an early unit who would rather open a period box than a modern poly bag.

What a master rebuilding kit does in a TH350

The Turbo 350 gets its three ratios from a compound planetary set and four multi-disc clutch packs: forward, direct, intermediate and low/reverse. A band holds the sun gear for manual 2nd, and two roller clutches handle the overrun. Shift points come from the vacuum modulator and the gear-driven governor, so there is nothing electrical to blame on a 1969-era unit. When it fails, it is almost always friction material that has worn thin or oil escaping past a seal, ring or worn bore before it can apply a piston. A master kit answers both halves of that problem: new frictions and steels for the packs, and fresh rubber, lip seals and gaskets so every piston sees full apply pressure again.

Symptoms that point to an overhaul

• A 1-2 shift that flares the engine, or Drive that seems to start in 1st and jump straight to 3rd
• 3rd gear and Reverse both missing, the classic sign of a burned direct clutch pack
• Delayed engagement into Drive or Reverse after the car sits overnight
• Dark fluid with a burnt smell and clutch lining in the pan
• Leaks at the front seal, shift shaft, pan rail and modulator all at once on a long-parked unit

How to confirm the transmission needs it

A TH350 that shifts badly is not always a TH350 that needs a rebuild. Check the fluid hot on the dipstick, pull the vacuum hose off the modulator and look for ATF inside it, and confirm the TV/kickdown linkage is adjusted. Our TH350 common problems guide explains how the missing gear tells you which pack has failed, and the delayed engagement guide covers the pump and bore leaks that cause slow Drive and Reverse. If a gear is gone outright or the pan is full of debris, plan on the overhaul.

Fitment

The box is marked for the 1969-up Turbo-Hydra 350. GM changed clutch plate counts and thicknesses by model code over the years, and the 1980-up TH350C lockup units brought their own internal changes, so a 1969-up label does not guarantee every plate matches a late unit. Before you order, read the model code on your transmission tag and send it with your vehicle year and VIN; we will confirm the kit suits it. Every Turbo 350 part we carry is on the TH350 parts page.

Install notes

• This is decades-old stock. Open the box on arrival, inventory it against your teardown, and flex the rubber seals and O-rings. Anything that has gone hard or cracked should be replaced with fresh rubber before it goes in the case.
• The listing names gaskets, seals, plates and steels. It does not list bushings, a band or a filter, so budget for those separately and measure every bushing during teardown.
• Inspect the pump gears and pocket, drum bores and the intermediate roller outer race. A worn pump wastes new frictions; a remanufactured TH350 pump for 1969 or a TH350 input drum costs less than a second teardown.
• Soak the frictions in ATF before assembly, set clutch pack clearances to the GM figure for your model code, and check end play.
• Fill with a licensed DEXRON fluid and finish the level on the dipstick with the engine running and the fluid hot.

For a realistic look at the rest of the bill, see what drives TH350 rebuild cost.

Is this a new kit or a used one?

It is new old stock: never installed, in the original sealed Windsor Products box marked 38000, Turbo-Hydra S.T. "350" 1969-UP. Because it is decades old, inspect the rubber seals for hardness or cracking before installing them.

What is in the box?

The listing states it includes gaskets, seals, friction plates and steel plates for a TH350 overhaul. Bushings, a band and a filter are not listed, so plan to buy those separately if your teardown shows wear.

Will it fit my 1979 or later TH350C?

The box is labeled 1969-up, but GM changed plate counts by model code and the lockup TH350C added its own parts. Send us the model code from your transmission tag plus your year and VIN and we will confirm before it ships.

What fluid should I use after the rebuild?

Use a licensed DEXRON automatic transmission fluid. Fill the pan, start the engine, run it through the gears, and finish the level on the dipstick with the fluid at operating temperature.

Should I replace anything else while it is apart?

Measure the pump, bushings and drum bores, and check the intermediate roller outer race for cracks at the lube holes and splines. Many builders also add a shift kit or a recalibrated valve body during the overhaul.

• TH350 Common Problems and Fixes: Modulator, No 2nd, No Reverse, Worn Bores
• TH350 Rebuild Guide: Known Wear Points and Upgrades
• TH350 Rebuild Cost and What Drives It
• TH350 Delayed Engagement: Causes and Fix