The purpose of a drive belt is to give power to the tractor or mower which in turn propels it forward. Like all drive belts on heavily-used equipment, John Deere drive belts eventually get worn and need to be replaced. If the belt is frayed or severed in any way, it must be replaced. The job is one you should be able to do on your own, but assistance is available through your John Deere Retailer both for purchasing and for technical support.
Remove the nut and pinion using the socket wrench and appropriate socket. The nut and pinion are located underneath the steering shaft at the front of the lawn mower tractor. Put the nut and pinion to the side for later reassembly.
Move the steering shaft upward and wrap the new drive belt loosely around the shaft. Pull the steering shaft back down and reassemble the nut and pinion.
Loosen the nut on the engine pulley with the socket wrench and pull down the pulley so that it clears the belt guides. The belt guides are little metal arms that ensure that the belt does not fly off during rotation.
Slip one half of the drive belt around the engine pulley and retighten the engine pulley using the socket wrench.
Locate the transmission pulley above the fan of the engine and loosen the nut attached to it with your socket wrench. Slip the back end of the drive belt over the pulley.
Loosen the bearings on the idler pulleys located in the middle of the belt on the underside of the tractor with your fingers. The idler pulleys will be circular in appearance. Do not remove them, only loosen them. Engage the parking brake to give slack in the belt. Intertwine the belt, starting on the right hand side of the idler pulley, and pull the belt through the belt guides.
Tighten the bearings on the idler pulleys making sure there is a little bit of play and disengage the parking brake to tighten any slack in the drive belt.