How the Transmission Kickdown Cable Works

by Alexis Writing

One of the many essential parts of a carbureted or fuel injected vehicle is a transmission kick down cable. The transmission kick down cable works to shift the transmission to a higher gear automatically when the engine is revved or otherwise accelerated. A kick down cable comes installed standard on any vehicle, but there are also a variety of aftermarket kick down cables that can be purchased as well.

The Importance of Length

One of the specifications of the kick down cable that is essential is the length of the kick down cable. The cable is set to a certain length with a slight amount of play available for final adjustment. If the cable is given too much slack, the transmission will be slow to shift into the next gear. If it is not given enough slack, the kick down will happen prematurely, with loss of power and other undesirable results.

Mounting and Operations

The kick down cable is mounted to the carburetor, or, in the case of fuel injected vehicles, the throttle body. It runs from the butterfly arm on the carburetor down to the side of the transmission, where it attaches to an arm that allows the transmission to shift gears. This is required by the vehicle as the carburetor or throttle body butterfly opens to cause more fuel to enter the engine, causing higher revolutions of the engine and increased speeds.

Springs

There is sometimes one--and possibly two--springs involved in the operation of the kick down cable. These springs serve to pull the throttle butterfly back into the lower position when the driver takes his or her foot off of the gas pedal. This also serves to pull the kick down cable automatically back down into the lower gear as the need for higher gear due to increased engine revolutions per minute is decreased. These springs can cause problems if they break or wear out. They are a good place to start looking if you have a kick down cable problem.