The primary cover on the 2005 Harley-Davidson Fatboy covers the chain used to connect the engine’s crankshaft and the transmission. If you need to service the primary chain, you must drain the primary fluid and remove the primary cover from the left side of the motorcycle. This will give you access to the crankshaft sprocket, primary chain and the transmission output sprocket.
1. Locate the drain plug on the bottom right corner of the primary cover on the left side of the Fatboy. Remove the drain plug and drain the primary fluid into a drain pan. Use an Allen wrench to remove the plug.
2. Remove the Allen-head bolts that secure the primary cover to the engine and transmission using an Allen wrench. Depending on the engine size and transmission, you will locate between 10 and 14 bolts.
3. Pull the cover off the engine and transmission. Be prepared to clean up some oil with a towel. In most cases, not all of the oil drains through the plug.