If you engage the Power Take-Off switch (PTO) on your John Deere LX172 tractor and there is a grinding sound or the blades will not turn, it's time to replace the electric PTO clutch. To engage the lawnmower blades on the LX172, you must pull up on the PTO located on the dashboard on the right side of the steering wheel. That sends a 12-volt current to the electric PTO clutch and starts the cutting process.
Park the lawnmower on a level surface and set the parking brake. Remove the key from the ignition.
Push the mower deck height adjustment into its lowest position. The height adjustment level is located below the seat.
Unhook the belt tension arm located on the right side of the lawnmower cutting deck. Push the tension arm all the way forward toward the front wheels.
Remove the primary deck belt connecting the electric PTO to the mower deck. Slide the belt off the pulley on the electric PTO clutch and then the pulley on the mower deck.
Lift the front of the lawnmower with the jack. Make sure to place the jack under the frame and not the axle. Slide the jack stands under the frame just in front of both front tires. Lower the jack until the frame is supported by the jack stands.
Remove the wire harness connector located on the top of the PTO clutch. Lift the tab on the top of the connector with a flathead screwdriver and pull the connector off the PTO clutch that is located under the frame and is bolted to the engine crankshaft.
Remove the bolt that holds the clutch to the crankshaft using an air wrench and 5/8-inch socket. Place one hand under the clutch to support its weight. The PTO clutch will slide off after the bolt is removed.
A manual socket wrench cannot be substituted for the air wrench and compressor for this job.