The Cub Cadet LT1042 riding lawn mower is one of the most popular models Cub Cadet manufactures. As is true with many riding mowers, the Power Takeoff (PTO) clutch, which engages the mower's cutting deck, can become worn over the years or with heavy usage and will need to be replaced. If your mower runs but the blades do not turn when the clutch is engaged, the PTO clutch is almost certainly bad.
Prepare to Replace the PTO Clutch
To replace a PTO clutch, a ratchet set, jack and breaker bar are needed. Take safety precautions and wear eye protection. Make sure the ignition key is in the "Off" position. Place a wheel chock behind the rear tires to help keep the mower from inadvertently moving while performing the repair and engage the brake. Once these safety measures have been taken, open the engine cover and remove the spark plug wire.
Access the Engine
Lower the deck so it is positioned in its lowest setting. Remove the belt from the idler pulleys that are located on the top of the deck. Next, locate and remove the spring loaded support pins on each side of the mower deck. Upon removal of the pins, set all parts aside in a secure container and slide the deck forward. Place the floor jack under the front of the mower and jack it up until you have clear access to the bottom of the engine.
Locate and Remove the Old PTO Clutch
Locate the PTO clutch, which will be attached to the bottom of the crankshaft, and use a ratchet to remove the bolt holding the PTO clutch in place. Should extra leverage be needed to do this, use the breaker bar. Before removing the old PTO clutch, make sure to remove the plastic wiring harness that is attached to it and set the harness with the other parts. Lower the old PTO clutch and stow it safely a few feet from your work area.
Install the New PTO Clutch
Put the new PTO clutch in place. Secure it using a ratchet to tighten the mounting bolt. Use the breaker bar carefully to tighten the bolt if additional leverage is needed. Once the clutch is secured, attach the new PTO clutch to the plastic wiring harness. Check all connections to ensure that everything is securely in place. Remove any tools that may be under the Cub Cadet.
Test the New Clutch
Slowly release the jack and lower the Cub Cadet until it is safely on the ground and the jack can be removed. Slide the mower deck back in place and re-secure it using the support pin on each side of the deck. Put the belt back on the idler pulleys. Reattach the spark plug to the spark plug wire. Close and secure the engine cover, then remove the wheel chocks from the back wheel. Start the Cub Cadet and lower the mower deck. The blades should now engage.
Swapping the old PTO clutch for a new one is about a two-hour repair depending on skill level. If this method does not fix the issue, you may have to take your Cub Cadet to a professional service center to isolate and fix the problem.