Murray riding lawnmowers have one or more blades mounted under the cutting deck depending on the model and cutting width. The removal of the cutting blades from a Murray riding mower is necessary in order to perform routine maintenance such as sharpening the blades or when it is necessary to replace a damaged or worn blade. Blade removal requires that the deck of the Murray mower is raised so that there is room to work under the deck.
Park the Murray riding lawnmower on a level area of the yard or on a driveway. Set the parking brake and place the transmission in gear so the mower will not roll while the blade is removed. Remove the key from the ignition to prevent accidental starting.
Raise the cutting deck to the highest position possible. Make sure the height adjustment level is securely in place so that the deck will not accidentally lower while work is performed.
Put on a pair of leather work gloves to protect hands while working. Place a block of wood against the inside of the deck. Turn one of the mower blades until it contacts the wood and continue pushing to wedge the wood in place to prevent the blade from turning.
Loosen and remove the blade nut on the mandrel that holds the blade, washers and adaptor in place. Use a socket, box-end or adjustable wrench to loosen and remove the nut.
Set the nut aside and remove the washers, blade and adaptor. Pay attention to the order in which the washers are assembled in relation to the blade so that the assembly can be replicated when a new blade is installed.
Position the block of wood under the deck so that the next blade to be removed wedges the wood and the blade does not turn. Remove the nut with a wrench following the same process.
Install a new replacement blade on the mower by sliding the adaptor onto the mandrel followed by the blade. Position the blade so that the turned edges of the blade turn up, not down, toward the ground.
Place the large Belleville washer on the mandrel below the blade followed by the smaller fender washer. Finger-tighten the nut onto the mandrel and securely tighten it with the wrench. Repeat the installation process for the second blade. Use the block of wood to wedge the blades and help with tightening.
Remove the block of wood from beneath the deck and lower the deck to the desired cutting height for operation.