Keep your treadmill belt clean, which helps keep the motor and motor controller from overheating. By keeping the temperature lower on your treadmill motor, you can lengthen the life of your treadmill. Clean your belt weekly using water and a nylon bristle brush and let the belt dry completely before you use it again.
Check the level of your floor if your treadmill belt moves from side to side as you walk on it. Move your treadmill to a level floor if necessary.
Check the front and the back of the treadmill if your treadmill belt moves from side to side. Replace broken endcaps if your treadmill has cracked plastic endcaps at each end. Your treadmill's bolts can pull through the plastic, which creates uneven pressure on your belt.
Replace the walking belt of your treadmill if your treadmill shuts down while you are using it. This can happen when the heat sensor of your treadmill shuts down the motor to prevent it from burning out. Keep the walking belt clean and maintained after you replace it.
Follow the manufacturer's directions on your treadmill for belt tracking if you hear a knocking noise while you're running on your treadmill. This can mean you have a defective roller, but it could also mean your belt is getting too much force on each side of the roller.
Adjust the treadmill belt to keep it from stretching by using the Allen wrench that came with your treadmill. An Allen wrench has an L-shaped bar and a head that looks like a hexagon. Use a similar-sized wrench if you didn't receive an Allen wrench. You will see the screws for the belt adjustment at the back of your treadmill. Make a quarter-turn clockwise to tighten the belt if you find it has become loose. Make certain your treadmill runs at three mph while you adjust the belt tracking. Three mph represents the ideal speed when making screw adjustments.