The Cub Cadet Z-Force, also known as a RZT series zero turn lawn mower, uses a traditional drive belt to run the mower deck. Although the engine mounts to the back of the mower, a PTO pulley still runs off the clutch system on the bottom of the engine. The PTO pulley applies power to the pulleys on the mower deck to turn the mower blades. If you hear squealing or you see dry rotting on the belt, you must replace it with a new one to correct the issue.
Position the Z-Force mower on level ground, set the parking brake and turn off the mower blades by placing the PTO lever to the "off" position." Turn off the ignition key on the mower to stop the engine and then remove the key to disable the vehicle from accidentally starting. Never work on the mower deck with a running engine.
Lift the mower deck into the upright storage position with the mower deck lift lever. You use this same process when you store your mower.
Locate the idler pulley in the center of the mower deck. It mounts to a spring-loaded metal plate. Rotate the metal plate away from the belt and then slip the belt off the pulley. Let go of the metal plate. This takes tension off the belt.
Look under the rear of the mower and locate the PTO drive pulley mounted directly under the engine. Rotate the pulley by hand as you pull the belt off the pulley.
Draw a diagram of the belt routing around the pulleys on the deck and then remove the belt from the deck.
Place the new belt onto the deck following the diagram you drew. It is vital that you install the belt with the correct routing to ensure the blades spin properly. Use OEM part number -754-04045 for 42-inch mower decks or use OEM part number 754-04240 for 50-inch mower decks. Use OEM part number 754-04138 for 54-inch mower decks.
Push in on the metal plate that holds the idler pulley and then slip the belt onto the pulley.