How to Sharpen Your Walk Behind Lawn Mower Blade
Your Cub Cadet walk behind lawn mower is useless without a sharp cutting blade. The only way to achieve a quality cut and healthy lawn is to regularly replace or sharpen the blade on your lawn mower. To determine if it’s time for a blade sharpening or replacement, periodically inspect your lawn and lawn mower. If you see unevenness in your lawn or notice the tip of grass blades are torn and not cleanly-sliced, it’s time to sharpen or replace your lawn mower blade. Additionally, if your Cub Cadet lawn mower blade has dings, nicks or rust, then it is time to upgrade your blade.

Here’s how to sharpen the blade on your Cub Cadet walk behind lawn mower.

Before performing any maintenance on your lawn mower, refer to your owner’s manual for maintenance and safety information. Maintenance instructions vary by model. Depending on your model number, these instructions may vary. Be sure to refer to your owner’s manual for detailed instructions.

First, disconnect the spark plug wire from the spark plug to prevent accidental starting. Then turn the mower on its side to remove the lawn mower blade – make sure the air filter and carburetor side is facing up.

Place a block of wood between the blade and the frame of the mower to support the blade as you apply force to remove it. Remove the hex bolt and the blade bell support holding the blade and blade adapter to the engine crankshaft. Take the blade and adapter off the crankshaft. Remember, cutting blades are sharp so always wear heavy duty gloves when working with them.

Sharpen the blade with a mower blade sharpener, file, or on a grinding wheel. Do not try to sharpen the blade while it is still on your mower.

Secure the blade in a vice when sharpening with a file or hand-held grinder. When you sharpen the blade, follow the original angle and grind. To keep the blade balanced, grind each cutting edge equally. To test the blade balance, remove the blade and balance it on a round shaft screwdriver. Shave metal from the heavy side until the blade balances evenly.

Before placing the blade back on your lawn mower, lubricate the blade adapter and crankshaft. Lubricate the crankshaft and inner surface of the blade adapter with light oil and then slide the blade adapter onto the engine crankshaft.

Replace the blade adapter. The side of the blade marked “Bottom,” or with the part number, should face the ground when the mower is in operating position. Make sure the lawn mower blade is aligned and seated on the blade adapter flanges. Place the blade bell support on the .

Align the notches on the blade bell support with the holes in the blade. Replace and tighten the hex bolt by hand. Place the block of wood between the and the mowing deck housing again and tighten the hex bolt to the torque recommended in your owner’s manual.

Turn the lawn mower right side up and reconnect the spark plug. Start your lawn mower and listen for noises or vibration. Adjust the blade balance if necessary.