Annual maintenance of a riding lawn mower includes lubrication of grease fittings, as well as an oil change, blade maintenance and adding fresh gasoline. Most homeowners perform annual maintenance after off-season storage and before the first use of the year. Mower spindles are located on each blade and on the front tires. A spindle is an area where two metal pieces attach and move in different directions. Grease fittings, known as zerk fittings, exist on each spindle to easily grease them and keep the lubrication inside joints without the need to remove parts.
Park a riding lawn mower on a flat, solid surface such as a driveway. Turn the ignition off and allow the mower to cool for at least 10 minutes. Lower the mower deck to its lowest setting for easy access to grease fittings.
Turn the head of a grease gun counterclockwise to unscrew it and pull it straight off. Pull the plunger rod at the base of the barrel backward out of the grease gun. Push the release latch down to lock the plunger in place. Pull the plastic tabs off both ends of a No. 2 all-purpose grease cartridge and insert it in the top of the barrel. Replace the head and release the latch. Screw a zerk fitting onto the head clockwise. Press the plunger inward slowly to start the flow of grease.
Lie down on the ground next to the riding lawn mower. Locate the zerk grease fittings on the mower blade vertical spindles. There is one spindle for each blade on the mower. The zerk fittings are metal nipple-shaped areas on the front of each spindle.
Wipe off any dust, debris or grease on a zerk fitting. Insert the tip of the grease gun fitting over a zerk fitting and press it downward. Hold the barrel of the grease gun in one hand and push the plunger inward slowly to fill the joint with grease. When grease flows out of the fitting, it is full. Pull the grease gun tip off the fitting. Wipe any excess grease off the fitting. Repeat with the other blade spindles.
Lubricate the grease fitting on each front wheel spindle in the same manner. The fittings are on the spindles just inside each wheel. Turn the lawn mower steering wheel side-to-side to distribute the grease in the wheel spindles.
Wipe excess grease off the tip of a grease gun before storing it. This will preserve the grease cartridge for future use.