How to Replace the Drive Belt on a Riding Mower

Park on a flat surface, engage parking brake, remove key, and disconnect the battery's negative terminal.

Locate and photograph the current belt routing before removing anything. Some mowers have a routing diagram on a sticker under the hood.

Lower the mower deck to its lowest position. Remove the deck if needed for access (consult your manual — some require deck removal).

Locate the belt tension spring and idler pulley. Release the tension — usually by moving the idler pulley with a wrench to create slack.

Slip the old belt off the pulleys, noting which pulleys it wraps around and in which direction.

Route the new belt following the same path as the old one (use your photo or diagram). Make sure it sits in the pulley grooves, not riding up on the edges.

Reinstall the tension spring/idler pulley. The belt should have some tension but still deflect about 1/2 inch when pressed.

Reinstall the mower deck if removed. Reconnect the battery.

With the mower on a flat surface, test the drive system at low speed. Listen for squealing (too loose) or excessive tension. The belt should engage smoothly.