Mower decks are available in many sizes, ranging from 22 inches for a push mower, all the way to 72 inches for a large commercial mower. A 22-inch mower has one blade, whereas a larger mower has two or three blades. No matter how large your mower is, blade maintenance remains the same. Blades should be sharpened and balanced at regular intervals. Depending on how often the mower is used, at some point the blades must be replaced. Replacing a blade is actually easier than sharpening a blade. Do the job yourself, and save time and money.
Position the mower on a hard flat surface such as a sidewalk or driveway. Engage the mower's brake, and then place a chock behind each rear tire.
Place the floor jack at the front of the mower, and center it on the mower body, between both tires. Raise the mower approximately 12 inches.
Lift the foot rest, and on the mower deck locate the nuts on each of the three blade attaching bolts. Using the correct sized socket on the impact wrench, remove each nut.
Reach under the mower, and pull each blade free of the spindle shaft, along with the bolt.
Slide the spacers, if there are any, and blade off each bolt. Slide the new blade, and then the spacers back onto each bolt.
Push each bolt with the new blade back up through the spindle shaft, and secure the nuts using the impact wrench.
Drop the foot rest back into place. Release the floor jack, allowing the mower to fall back to the ground.
Remove the chocks from the rear tires.