Lawnmowers need regular upkeep to prevent damage to both machine and lawn. Although most mower owners change their mowers' oil and air filter regularly, many neglect their mowers' cutting blades. An old, worn out mower blade will cut grass unevenly and is likely to wobble. It can ruin the engine's driveshaft and can be dangerous to the operator and bystanders. Replacing a mower blade every 2 or 3 years ensures the best cut possible and provides you an opportunity to remove caked-on grass from the mower deck.
Remove the gas and oil from the mower according to your model's instructions. Disconnect the spark plug to prevent the mower from starting.
Tilt the toro mower onto its side, making sure to tilt it in a way that leaves the gas tank below the carburetor to prevent gas from leaking into the carburetor.
Immobilize the blade by wedging a piece of wood between the blade and the mower deck.
Loosen the one or two blade nuts from the blade. If the bolts are stuck, hit the handle of the wrench with a rubber mallet in the loosening direction to get it started.
Remove and discard the old blade. Clean away caked grass clipping matter, then attach the new blade. Make sure the blade retaining nut is tightened securely before you turn the mower back upright.