How to Take Off Mower Blades on a MTD LT 4200

MTD produces a variety of mowers for homeowners with medium to larger-sized yards. The MTD LT 4200 features dual blades that allow a wide path of grass to be cut with each pass across the yard. As part of the routine maintenance associated with the mower, removing the blades is necessary when they are damaged or require sharpening.


Park the MTD mower on a flat and level surface in the yard or on a hard surface such as a driveway. Leave the transmission in gear, set the parking brake, and raise the cutting deck to the highest possible setting to allow access to the blades.


Raise the engine hood and locate the spark plug wire. Grasp the rubber boot on the end of the wire and pull it from the tip of the spark plug. Put on work gloves to protect your hands while working under the mower deck and handling the cutting blades.


Lay down beside the raised mower deck. Place a block of wood along the inside of the cutting deck against the baffle. Hold the wood block and rotate the blade until it makes contact with the block, wedging it in place to prevent the blade from turning while removing the blade.


Locate the nut and washer assembly in the center of the cutting blade. Loosen and remove the spindle nut assembly with an adjustable wrench. Turn the nut counterclockwise to loosen and remove. Set the nut and washer assembly to the side for use later.


Examine the blade for damage, such as chips and cracks. Obtain a suitable replacement blade, if necessary, or sharpen the blade with a metal file. Purchase a blade from a mower repair shop, hardware store or home improvement store.


Sharpen the blade by running the file across the beveled side. Make the same number of passes on both ends of the blade to remove the same amount of metal and keep the blade in balance. Place a screwdriver in the center hole of the blade to determine the balance. Remove additional material from one end of the blade if necessary, until the blade balances levelly on the screwdriver.


Place the blade back on the spindle under the mower deck. Position the blade with the turned edges pointing up toward the mower. Secure the blade in place with the nut and washer assembly. Tighten the nut with the adjustable wrench.


Repeat the process for the second blade. Connect the spark plug wire back to the spark plug tip when you have finished.