Information on How to Replace the Belts on Tractor-Type Lawn Mowers

Locate the belts underneath your lawn mower. Check them regularly for signs of wear, shredding or defects. Look for cuts, slices and breaks in the belts. Replace the belts every four or five years, before they break. Park the lawn tractor inside the garage or on a paved, level surface outdoors. Shut off the engine, take out the key and unhook the spark plug so there's no chance of the engine starting. Set the parking brake.

Buy the correct belt for your brand and model of mower. Use the lift-lever to lower the deck down to its lowest position. Remove the belt guards and the keeper rod on the engine pulley with a ratchet and socket. Loosen up the idler pulley nuts. Take a picture of the belt before you remove it so that you can remember how to route the replacement. Remove the old belt and route the new belt around the pulleys. Replace the guards and keeper rod. Tighten the idler pulley nuts.

Locate the lawn tractor's drive belt. Look for a V-belt going around the main drive gear and a clutch pulley. Make sure you have the right replacement belt by matching the part numbers. Park the lawn tractor on a level, flat surface. Shut off the engine, engage the parking brake, disconnect and ground the spark plug. Let the engine cool down.

Take off the cutting deck by removing the attaching bolts with a ratchet and socket or open-end wrenches. Remove any cotter pins holding the deck in place. Disconnect the negative cable and then the positive cable. Lift out the battery for better access to the belt. Locate the large transaxle pulley and loosen the big nut holding it to the power input shaft. Use a spring puller to relieve tension on the forward-and-reverse upper drive belt by removing the springs from the anchor bolts.

Take off the upper drive belt by maneuvering it off the transaxle pulley. Remove the lower variable speed belt, if your mower has one, by taking off the guides and keeper bar. Unbolt the crankshaft pulley. Pull out the lower belt. Put in the new belt. Refer to reference photographs for proper routing. Reinstall all parts and tighten all bolts for the lower belt. Install the new upper belt, routing it around the variable speed pulley and the transaxle pulley. Put the tension springs and mower deck back on.