The TH350 (also known as Turbo Hydra-Matic 350) is widely recognized by auto enthusiasts to be amongst the finest three-speed automatic gearboxes ever produced.
It was originally produced as a replacement for the Powerglide transmission and debuted in 1969. Buick and Chevrolet collaborated on the Turbo 350, which was jointly developed and manufactured. It was also known as the CBC350, or the Chevy-Buick Combined Transmission, owing to its two natures. The TH350 has a good balance of strength and compactness, making it suitable for smaller automobiles.
At least until 1984, the Turbo 350 was well-known in rear-wheel vehicles, including both automobiles and trucks designed by GM. The Turbo 350 was designed to work with small-block V6 and V8 engines, but it began to be phased out in 1982 and replaced by the 700R4, which remained in production until 1984. Because of its power, the Turbo 350 is also effective in a vehicle.
For years, the Turbo 350 was referred to as a three-speed Powerglide by auto technicians, which makes sense since it was based on the Powerglide. This was its alternative name during development. It has a torque converter that is identical to the one on the TH400, but it is most comparable to the Chevrolet original 1962 Powerglide. The only distinction between them is that the torque converter did not have a variable pitch stator.
The Turbo 350’s distinguishing feature, at least in comparison to the 400, is that it lacks significant central support. This eliminates the need for a separate transmission, resulting in a lighter and more efficient vehicle. This also allowed Corvair’s engine to be integrated into the Turbo 350 design. The two ends are identical, which would not be the case if there was central support for the transmission.
From 1972 through 1978, the TH350 got aerodynamic received a baffle on the torque converted, including air intakes and an air baffle, which allowed for airflow cooling. If not properly maintained and cleaned, though, air intakes might expose debris into the internal components. The Nova 6 and Vega are two of Chevrolet’s most well-known vehicles equipped with air-cooled gearboxes.
The main drawback of the Turbo 350 is excessive play at the end. The clutch drum wobbles as a result of this. When a drum and pump are subjected to more stress from play, they undergo additional strain. In excess of what would have been the case if there was no play, it put an added burden on the drum and pump. Fortunately, it’s a simple problem to fix. Just insert a thrust washer in the middle of the clutch and the main planetary gear. The end play is eliminated as a result of this. A thicker bushing may also be installed in the drum instead of the original one.
You should also think about upgrading to a more robust case to safeguard the central splines and strengthen the support. Otherwise, the case may fracture and impair the internal components.
Turbo 350 Shift Kit
The Turbo 350 is a 24-inch long entirely aluminum alloy cast engine with an integrated bell housing. It’s rather light at just 120 pounds. A chamfer is present at the rear passenger side of the oil pan, which was custom-made to fit it. The modulator may be viewed on the back of the case.
The Turbo 350-C was a unique variant of the Turbo 350 that was equipped with a locking torque converter. This model was only produced for five years, from 1979 to 1984. When the car was driven at highway speeds, it used electronic converters to improve fuel efficiency. If you have a 350-C on your hands, look for a plug on the left side. Adding aftermarket conversions to these transmissions allows you to make them profitable today, with a potential 10% increase in fuel efficiency.
Turbo 350 Shift Kit Features
It’s conceivable that the TH350 has a different clutch and band specifications. Similar to motherboard/computer processors, transmissions are linked to motors. The stronger the motor, the more powerful the transmission. Even if the transmission is light-duty, it may be improved with inexpensive components.
The new shift improver kit is a good example of this. They may prevent clutch wear, increase heat dissipation, and improve shifts in general. A stronger torque converter can also be installed if required to match the power needs of your car.
Turbo 350 Shift Kit: Engine Compatibility
The Chevrolet small and big block engines, V6 or V8, may all be used with the standard Turbo 350. You may also link it with the I6, which is a single-cylinder in-line engine with six cylinders. Another potential compatible engine is the Duke I4. The BOP (Buick, Oldsmobile, and Pontiac) is a variant of the standard TH350 that works with the Pontiac V8. Look at the block flange to distinguish the two types. The Chevrolet model has a peak, while the BOP version has a valley.
Look at buying a TH350C Unicase if you want the best of both worlds. It works with Ford, Chevrolet, Buick, Oldsmobile, and Pontiac engines. It has a lockup torque converter, which is necessary for smooth shifting. The C mark etched adjacent to the pump bore distinguishes this gearbox.