TH350 valve body for 1969-1986, remanufactured and ready to install. Ships fast from the USA.
A 1969-1986 Chevrolet, GMC, Pontiac, Oldsmobile or Buick with a TH350 that shifts soft, mushy or inconsistent - but still needs to work as a normal automatic in daily traffic - is the exact case TCI built this valve body for. It's a direct-fit TH350 unit (321001) that keeps full automatic shifting through the TV cable and governor but firms up the shift feel and holds each gear longer under load than a stock-calibrated casting tuned for a soft factory ride.
The valve body is the hydraulic control center of the TH350. It takes line pressure from the pump and routes it through a casting full of precision bores and spool valves to apply the clutch packs and bands in the right order at the right pressure. On a stock unit, the pressure regulator spring and boost valve are calibrated soft for a smooth, barely-felt factory shift. TCI's valve body changes that calibration so the clutches apply with more authority - the transmission still shifts entirely on its own through the TV cable and governor, it just shifts firmer and holds pressure better under the load a stock casting wasn't built for.
Soft or slipping shifts can trace to a worn valve body, a maladjusted TV cable, a failing modulator, or clutch wear deeper in the transmission, so it's worth ruling those apart first. Our TH350 valve body problems and testing guide walks through isolating a worn bore from a cable or modulator issue, and our harsh shift causes guide covers the difference between a shift that's firm because of this kind of valve body and a shift that's harsh because something is actually failing.
This unit is built for the TH350 across the 1969-1986 production run, but the TH350 went through multiple casting and governor updates over those years, so confirm your current valve body's part number against 321001 or send us your year and VIN before ordering. See the full TH350 parts collection for the stock-calibration and full-manual versions of this valve body if a firmer-shifting automatic isn't what you need.
Drop the pan and replace the filter and gasket at the same time you install the valve body so debris from the old unit doesn't circulate through the new one, and torque the case bolts in sequence to spec. The TH350 is a fully mechanical, TV-cable and governor-controlled transmission with no onboard computer, so there is no electronic relearn after install - instead, check and adjust the TV cable to the correct preload once the valve body is in, since an improperly adjusted cable will make even a correctly calibrated valve body shift wrong. Refill with Dexron ATF, and pair the job with a governor shift point kit if your shift points have been drifting, since the governor and this valve body work together to set when each shift happens.
| Transmission | TH350 |
| Year Range | 1969-1986 |
| Condition | Remanufactured / updated |
| Shipping | Ships from the USA |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
It keeps full automatic shifting. The transmission still shifts on its own through the TV cable and governor - this valve body just firms up the shift feel compared to a stock-calibrated unit.
TCI recalibrates the pressure regulator spring and boost valve for firmer, more authoritative clutch application under load, where a stock casting is tuned soft for a smooth factory ride.
No. The TH350 is fully mechanical with no onboard computer - there's no electronic relearn. What you do need to check is the TV cable adjustment, since that's what sets shift feel and timing on this transmission.
It's built for that production run, but the TH350 had multiple casting and governor updates over those years. Confirm your current part number against 321001, or send us your year and VIN.
If the cause is a worn or soft-calibrated valve body, yes. If the cause is a maladjusted TV cable, a failing modulator or worn clutches, this alone won't fix it - check our testing guide first.
Dexron ATF.
