The vacuum modulator is a vital component of an automatic transmission. It tells the transmission what kind of load is being put on it allowing the transmission to react with the proper line pressures and shift points. Over time, modulators can develop leaks, get ruptured diaphragms, get bent, etc. Not only can this cause annoying drivablility issues, it can lead to premature transmission failure.

TCI comes to the rescue with this line of new, adjustable modulators. Not only will you renew performance, but you will also have the ability to slightly raise/lower part throttle shift points and line pressures. Simply adjust the screw inside the vacuum nipple for more or less diaphragm preload.