The larger MTD lawn tractors have an electric clutch to engage the mower blades. The clutch works off a 12-volt system; when the clutch PTO switch is engaged, an electrical current is sent to the clutch and the clutch brake engages, turning the pulley on the clutch. The pulley has a belt going back to the spindles on the mower deck, which turns the blades. When the electric clutch malfunctions, the blades on the mower deck will no longer turn. Changing the electric clutch will take 15 minutes to complete.
Park the lawnmower on a flat surface and remove the key from the ignition. Disconnect the negative battery cable from the battery post with the 3/8-inch wrench. Pull the spark plug wire from the spark plug.
Remove the pin from the front draft rod assembly on the front of the mower deck; slide the belt off the PTO clutch by hand. Slide the jack under the front of the mower frame. Raise the mower off the ground and slide the jack stands under each side of the frame in front of the tires. Lower the jack until the frame rests on the jack stands.
Disconnect the clutch wire from the wire harness on the right side of the clutch. Keep the clutch from turning by putting the 35mm wrench on the large washer above the bolt that holds the clutch to the engine's crankshaft. Remove the 5/8-inch bolt holding the clutch against the crankshaft.
Remove the bolt and washer and the clutch from the crankshaft. Apply multipurpose grease to the crankshaft on the engine. Install the new clutch, ensuring the pin coming down from the frame slides into the slot on the top of the clutch. Ensure the fixed key inside the clutch slides into the crankshaft keyway.
Install the washer with the concave side up towards the engine. Install the bolt and tighten down. Reconnect the connector from the wiring harness to the side of the clutch. Reconnect the spark plugs and negative battery cable. Lower the machine to the ground.