Alrighty - a month ago my father-in law and my son attempted to open the garage door with the slide bolt in place. Thus breaking the drive belt. After finally getting a drive belt I hooked it all up. Tension spring as instructed - hand tightened and then had the spring pop in place. When I went to see the "magic" - the door was in the closed position - it went forward as to close - the drive rail buckled - the door then came back a total of four inches. When the forward motion happened I heard some grinding of gears. I lessened the forward motion of the opener and the grinding ceased from occurring. However, again, the opener would go forward - hot the forward stop bolt and then back towards the up position and stop after four inches. I took the unit down and opened it up. The gears seem fine, no breakage, but the motor was hot. Any ideas???