How to Stabilize Treadmill After placing unit where it will be used, check its stability. Determine if there is even a slight rocking motion or unit is not stable. Determine which stabilizing leg is not resting on floor. Item Description Qty. 1 Base 1 2 Threaded stud 2 3 Stabilizing leg 2 Loosen jam nut. Turn stabilizing leg until rocking motion ceases, and both stabilizing legs rest firmly on floor. Tighten jam nut. Parent topic: Getting Started