Treadmills can cost hundreds if not thousands of dollars, yet a new walking belt is just $100. Often, the belt on an otherwise perfectly good treadmill will fail because it is the part that gets the most use. Save yourself a repair bill and install a new belt on a ProForm Treadmill. Specific instructions should come with your belt, but they will not be included in the manual that came with your treadmill.
Unplug your treadmill and remove the motor hood. If you do not see an adjustment bolt, mark the positions of the rollers on the bolt on the front and back of the treadmill. A permanent marker works well.
Take off the plastic side covers on the deck surface, but do not force them. If you see staples, slide the covers toward the back of the treadmill. If there are staples in the front and the rear, remove them gently with a screwdriver. This will break the plastic.
Loosen the walking belt by loosening the bolts on the motor and rocking it forward. The roller in the front now needs to be removed. Do this by either loosening the bolt on the side or wiggling the posts out of the holders. Do not remove the bolts from the roller in the rear.
The deck must be removed next. This should be as simple as undoing a few bolts or screws with your Phillips head screwdriver. If your treadmill has side rails, these must be removed first. See your owner's manual for instructions. You might be able to find a PDF file of your manual (see link in Resources).
Pull the belt off and put the new one on. Reverse these steps to finish installing your new belt.