If the truck has the stock gm cable it is self adjusting but first you have to set it up there is a button on the cable at the throttle body bracket. Depress the button and at the same time put the outer cable toward the trans You will see it move inside the bracket. releace the button give the it full throttle and the cable should move out. This if factory set it does not always get you where you want to be but it is very close. You can make small ajustments on click at a time by pushing in the button and carefully moveing the outer cable.toward the trans harder and later away from the trans sooner and softer .