1980 vette transmission


The lockup converter gives you another little up-shift like feeling when the converter locks up around 40 - 45 mph. The lock-up is controlled by two factors. First is a switch on the brake pedal. If you are off the brake, lockup can occur. If the converter is locked, when you apply the brake the converter will unlock and free wheel.
Second is vacuum, or engine load. There must be at about 5 lbs vacuum to the vacuum module on the drivers side firewall for the module to allow voltage down the wire going to the transmission to do the lock up. If the engine is under heavy load (acceleration) the vacuum switch will not receive enough vacuum and will again unlock the converter and let it act like a normal torque converter.
The 350C is a good transmission, but rebuilds can be costly, especially if you have to replace the converter.




