Locate the thin hex nut, known as a jam nut, on the clevis at the bottom of the auger drive control rod. Loosen the jam nut, using a jam nut wrench.
Remove the cotter pin and clevis pin that hold the clevis to the bent rod. Reserve the removed pins. The cotter and clevis pins are small; be careful to avoid losing them.
Rotate the clevis to adjust the auger belt tension. Turn the clevis counterclockwise to increase the belt tension or clockwise to decrease the tension.
Replace the removed cotter and clevis pins to hold the belt at the desired tension. Tighten the jam nut to lock it against the clevis.