I have a Sears Garden Tractor with a 48" mower deck. By working in long, thick grass I broke the mower belt -- not the one that transmits power from the engine, but the belt that sits in a pulley on the same shaft, and drives the three mower blades. I've dismounted the mower deck from the tractor, cleaned out the accumulated grass, and set the new belt in place (got the belt part number from the owner's manual and bought it from a Sears Parts and Service Center, so I feel I have the right one). Followed the manual's directions for routing the belt, but CANNOT get the belt over the last pulley. There's a very strong spring holding tension on that belt through an idler on a swinging arm, but with all pulleys in place I can't generate enough force to make the belt go over the pulley. If I disengage the spring, of course, the belt goes over easily -- but then I can't generate enough force to get the spring back into its notch. I've worked on this for a full day, trying to out-think the hardware, but have made no progress. Seems I need some way to make that spring stretch out and hold it while I roll the belt over the pulley. Can anybody offer a suggestion? Thanks.

Place the deck in the lowest position using the hydraulic piston (if applicable) or the manual cutting-height adjuster.

Remove the deck-to-PTO belt from the PTO by releasing tension on the idler-arm pulley. This is a spring-loaded handle that turns in only one direction by hand and relieves the tension on the belt. Slip the deck-to-PTO belt off the PTO pulley after the tension is relieved.

Remove the deck from underneath the mower or tractor.

Locate any belt stops and loosen them with the ratchet wrench and proper socket. Belt stops are located on the deck and are the small metal brackets that guide and secure the belt to the pulleys so it will not jump off when under heavy use, or stretch from normal wear.

Remove any pulley covers by removing the retaining screws using the ratchet wrench and a socket.

Loosen the idler-pulley retaining bolt (located on the underside of the mower deck) to replace the deck-to-PTO belt. Removing the bolt is not necessary. Loosen the pulley enough to wiggle the belt free from the pulley and remove and replace the belt.

Remove any arbor covers (if applicable) that conceal the arbor pulleys by removing the retaining screws with the ratchet wrench and a socket to replace the mower arbor belt.

Locate the tensioner pulley on the mower arbor belt to replace it. Loosen the tensioner pulley bolt enough to slide it and release tension from the belt. Remove the belt from the arbor pulleys and replace it.

Slide the tensioner pulley back leaving about 1/2-inch of play in the belt and tighten the bolt. Reverse the procedure to put the rest of the mower deck back together and reinstall on the mower or tractor.