How to Install a Lawn Mower Oil Seal

Make sure the lawnmower is turned off. You may wish to disconnect the spark plug wire of the lawnmower to prevent accidents.

Remove the existing oil from the lawnmower. Raise the machine on two concrete blocks or two thick wooden blocks so the underside is readily accessible. Slide an oil drain pan directly beneath the oil drain plug.

Remove the oil plug and allow all the old oil to drain into the pan below. Unscrew and remove the oil dipstick at the top of the mower while the oil drains from below. Wipe the dipstick clean with a rag, wipe the opening and lip of the oil fill clean as well and replace the dipstick once the old oil has drained.

Clean the oil drain plug with a rag and replace it. Tighten the plug with the correct wrench for your particular plug. Lower the lawnmower to a flat surface, such as your driveway, and turn it gently onto its side.

Fit a thick piece of wood beneath the blade of the mower so the blade is held fast and does not spin. Unscrew the central bolt affixing the blade with a socket wrench. Set the bolt aside and cautiously remove the lawnmower blade and any adapter pieces, setting these aside as well.

Find the oil seal, which should now be fully visible. It is often a black ring, though sometimes it may appear brown or slightly oval-shaped. Slip the edge of a flat screwdriver beneath the seal and pry it off the mower undercarriage.

Apply fresh oil to the new soil seal with your fingers. Be sure to use the oil that is appropriate for your machine. Fit the new seal into place, pushing it in securely with your fingers or the edge of the screwdriver.

Reinstall the lawnmower blade and any adapters. Turn the machine right side up and add new appropriate oil to the oil fill line on the mower’s dipstick. Reattach the spark plug wire if you detached it in Step 1.