Like other belts on a Cub Cadet lawn tractor, the transmission drive belt can become cracked or worn over time. Check all belts at least once per year for wear and tear. Changing this belt is a bit more complicated than others, but it can usually be done within an hour or so. Cub Cadet recommends replacing the transmission drive belt with a factory approved belt, typically available at retailers that sell this brand.
Park the tractor on a level place. Remove the mowing deck and place the front wheels on blocks or jack up the front end. Place wooden blocks behind the rear wheels to ensure the tractor doesn't move while it's being serviced. Disconnect the battery cables, removing the negative contact first.
Detach the PTO electrical harness underneath the engine. Loosen and remove the hex nut from the electric PTO clutch. Lower the PTO clutch nut off the crankshaft, making sure not to lose the nut or any accompanying washers.
Remove the old belt from the tensioner, or fixed V-idler, pulley. This round pulley is located midway between the PTO clutch and the transmission. Pull down on the engine pulley, which is located on the driveshaft, and remove the belt from the engine pulley. Continue unlooping the old belt from the pulleys. Remove it from the transmission pulley in between the rear wheels last. Discard the old belt.
Place the new belt on the transmission pulley first. Take care not to bend the transmission fan blades. Loop it back through the other pulleys in the reverse order in which it was removed.
Place the PTO hex bolt and any washers that were on the shaft back in place and tighten the bolt. Replace the mowing deck. Reconnect the battery cables, connecting the positive cable first. Lower the front end off the blocks or jack.