Where is the kickdown switch on a TH400?
Instead of a linkage or cable, the TH400 uses an electrical switch that is most often mounted on the carburetor. The 12-volt connection is a single spade connector just above the oil pan rail on the driver’s side about halfway back–at least that’s where it is on my TH400.
Does a Turbo 400 have a kickdown cable?
Did you know that GM’s Turbo 400 three-speed automatic transmission uses an electric switch instead of a cable or mechanical linkage to downshift a gear at wide open throttle? Our friend D.L.
How do I test a TH400 kickdown switch?
The kick down switch at the gas pedal can be tested with a multimeter(set on ohms). The solenoid in the pan can be tested by applying 12 volts to the vertical connection at the transmission and listening for a click emanating from the pan.
Are all Turbo 400 transmissions the same?
Both 2wd and 4wd versions of the Turbo 400 can be used equally well, and there are no inherent advantages to either one once you have installed our adapter assembly. It is of interest that the 1976-1979 AMC case, while more or less similar from the collar of the case, back, is tilted about four degrees.
Does a Turbo 400 need vacuum?
It must hold the vacuum for a few minutes without dramatic loss of vacuum or the diaphragm is bad. Shut off the engine and allow it to cool for 20 minutes. Remove the bolt in the modulator hold-down clamp using a wrench. Remove the clamp and with a slight twist, pull the modulator out of the transmission.
What’s the difference between Turbo 350 and Turbo 400 transmission?
The TH-350 was a low-torque transmission that was used in heavy cars. With modification, the TH-350 could be used as a high-torque transmission in a light car. The TH-400 was a high-torque transmission that was used in heavy cars — it was a much stronger transmission than the TH-350.
How does a Turbo 400 kickdown work?
When the throttle linkage reaches a specific point, the cable triggers a mechanical detent valve inside the transmission–allowing it to shift into a lower gear. The Turbo 400 uses an electric switch to trigger a detent solenoid on the valve body to produce the same effect.
What does the TH400 kickdown switch do?
How do you hook up a Turbo 400 kickdown?
This electrical input powers up a solenoid in the transmission that accomplishes the same results, with higher line pressure and a signal to downshift the transmission. Often when a TH400 is swapped into a different vehicle, this downshift electrical switch is overlooked.
What kind of kickdown switch do I need for TH400?
B&M kickdown switch kits are perfect for use when swapping out a TH350 or TH700R4 for a TH400. These kits mount to the factory throttle cable bracket for easy kickdown control.
Where is the kickdown switch on a Caprice 454?
Originally, our Caprice’s LS4 454 came with a Quadrajet carb and the kickdown switch was on a bracket on the driver’s side rear of the carb behind the linkage. There was a pad on the QJet’s linkage that hit a push button on the switch when you got the throttle wide open.
What does the vacuum modulator do on a Turbo 400?
What does the vacuum modulator do on a Turbo 400? It is equipped with a vacuum modulator that senses change in the engine’s vacuum due to throttle position and load changes. As these changes occur, the modulator adjusts the shift timing of the transmission according to the demand of the engine.