How to Replace a Lawn Tractor Blade Video


Learn how to replace a dull, chipped or broken blade on your lawn tractor in this Sears PartsDirect video. For additional troubleshooting tips and solution, step-by-step repair guides and answers to commonly asked questions, check out our riding mower and tractor repair help section.

How to replace a lawn tractor blade

Keeping a sharp mower blade is important to ensure a quality cut. This video shows how to replace the blade on your lawn tractor. You can order the new blade on or by calling 1-800-252-1698. Write down the exact model number from your tractor, including dashes, periods and other characters. You need this complete number to ensure you order the correct parts.

Tools and Equipment You Need

This job can be done by most people using basic hand tools. You will need safety glasses, gloves, a ratchet wrench with the correct-sized socket, a small putty knife, needle-nose pliers and a torque wrench to tighten the blade bolt. You may also need a 4x4-inch block of wood.

Before You Begin

First, park the tractor on a level surface and set the parking brake. Next, remove the key from the ignition switch. To eliminate any chance of the engine starting, raise the hood and remove the spark plug wire and tuck it away from the spark plug.

Remove the Mower Deck

To gain access to the blades, the mower deck should be removed from under the tractor.

Lower the mower deck to the lowest position. Make sure the mower deck is disengaged. Remove the mower drive belt from the engine pulley. On the left side of the tractor, remove the bow tie clip from the left rear lift arm and disengage the lift arm from the mower deck.

Then go the right side of the tractor, remove the bow tie clip from the right rear lift arm and disengage that lift arm.

At the front of the tractor, remove the clip holding the front suspension arm to the front of the mower deck.

Turn the front wheels to the left to make it easier to slide the mower deck out from under the tractor. Raise the mower deck lift lever to the highest position. This moves the lift mechanism out of the way. Slide the mower deck out from under the tractor. Disconnect the engagement lever cable from the mower deck.

Remove the Blade

Turn the mower deck upside down to gain access to the blades. If the bolt is extremely tight or rusted, you can wedge a block of wood between the blade and the mower deck to secure the blade. With gloved hands, hold the blade with one hand and use a wrench to loosen the blade bolt with the other hand.

Install the New Blade

Once the blade is removed, use a small putty knife to remove any grass buildup from the underside of the mower deck. Once the underside of the mower deck is clean, it’s time to install the new blade. The blade will be stamped with either “This side up” on the top or with “Bottom” or “Grass side” on the bottom. The mandrel shaft that the blade attaches to has a star pattern. The blade has the same pattern. The star in the blade has to fit onto the star on the mandrel.

Once you have the blade on the star, hold the blade with one hand. Then thread the blade bolt with the other. Holding the blade with a gloved hand, tighten the blade bolt with a torque wrench. The blade bolt should be tightened between 45 foot-pounds minimum and 55 foot-pounds maximum.

Reinstall the Mower Deck

Slide the mower deck under the tractor and re-hang the mower deck in reverse order in which it was removed. Now reconnect the spark plug wire. Lower the mower deck to the desired cutting height and your tractor is ready to mow again.

That’s all it takes to replace the blade on your Craftsman tractor.