Start your wood splitter and allow the engine to run for five minutes. Warm oil drains more quickly than cold oil. Shut the engine off after five minutes. Locate the oil drain plug on your wood splitter. The drain plug is usually near the bottom of the engine crankcase.
Place a container under the oil drain plug to catch the old oil. Unscrew the oil cap with dipstick from the top of the engine. Wipe the dipstick clean with a rag and wrap the rag around the dipstick. This prevents dirt and debris from sticking to the dipstick. Place the dipstick out of the way.
Loosen and remove the drain plug from the wood splitter engine with a socket wrench. Allow all of the oil to drain into the catch container. Once the oil stops dripping, insert the drain plug back into the crankcase and tighten it with the socket wrench. Wipe the area around the drain plug with a rag to remove oil residue.
Insert a clean funnel into the oil dipstick hole on the top of the engine. Pour 1 pint of SAE 30 motor oil into the funnel. Remove the funnel and unwrap the clean dipstick. Insert the dipstick into the fill hole and remove it to check the oil level. Continue adding oil until the level is at the full mark on the dipstick. Place the dipstick back into the engine and turn it clockwise to secure.