How can you keep your serpentine belt from falling off the pulleysI recently caused a dent to your front end that was already a dent from the first owner which now it loudly vibrates and the belt fall?

Answer 1

1. Visually inspect the serpentine belt and idler pulley to determine it misalignment exists. 2. Start the engine and let it run for one minute before checking alignment. (The belt should be approximately 2mm (0.08 in.) from the inboard edge of the idler pulley, when alignment is correct. 3. Remove the belt and inspect the idler pulley for looseness, wobble, or a defective bearing. If any of these exist, replace the idler pulley. 4. The basic operating principle of the automatic tensioning mechanisms for all serpentine drivebelts is the same: A sealed housing with a powerful spring is connected to an external arm or flange on which a pulley is mounted, usually held by a through bolt or possibly a stud and nut. The pulley is there to take up slack in the drivebelt when installed, and maintain enough tension on the belt. The spring housing has an external indicator that moves with the tension provided by the spring. The fixed part of the tensioner housing has maximum and minimum marks, and perhaps even a smaller range of marks for a new belt. When a belt has stretched, so that the tensioner spring indicator is very close to or against the maximum length mark, the belt should be replaced. Even if the spring tensioner seems to be holding the belt, put a wrench on it and move it slowly, feeling carefully for any lost motion in the spring tension. If you hear a clicking or feel anything but smooth tension, replace the tensioner. Tensioners go bad more often than you'd believe--they crack, their mounting bolts loosen, their pulleys become damaged, the bearing fails. 2. In the case of the Ford Escort ZX2, 2 Liter engine, stop wasting your time checking for worn idlers, bearings & belts. The problem is that a dummy engineer created the problem (that's why mechanics cuss so much -- dummy engineers). The tensioner is placed too far away from the grooved pulleys. The flat pulleys have no axial retention (side wander control). The solution is to replace the tensioner with a $20 Dayco or Duralast part # 231084. That part has flanges to retain the belt from falling off. You will need to shim the pulley out 3/32 inch, because the new part is plastic and interferes with the stud it mounts on right at the outside diameter of the bearing of the tensioner. I turned down some of the plastic on my engine lathe so I only had to shim the pulley out half that much. I didn't want to lathe off all the interference, because then the plastic pulley might fall off its bearing. On the outside of the pulley don't use the washer under the bolt head, because it interferes with the plastic (again right at the outside diameter of the bearing), and you don't need it. Good luck!