Why is the running belt not staying in the center of the treadmill or slipping during use?Updated 2 years ago

First, check to make sure the treadmill is level, then while standing to the side of the treadmill, start it at 3 mph and observe it for at least two minutes. Is the belt starting to center itself? If so, you may simply have a leveling issue. Use the adjustment feet on the underside of the treadmill to level the unit.
If the belt doesn’t center itself after two minutes, kneel down at the rear of the treadmill with a hex key in hand. If the belt is drifting to the left, insert the key into the left bumper and turn it a quarter-turn clockwise. Then insert the key into the opposite side and turn it ¼ turn counter-clockwise. If the belt is drifting to the right, insert the key into the right bumper and give it a quarter-turn clockwise. Then insert the key into the opposite side and give it a quarter-turn counter-clockwise. Observe the belt for at least 2 more minutes to give it time to center itself. If after those two minutes it doesn’t center, repeat the process one more time.