Proper maintenance is the key to keeping a Harley-Davidson motorcycle roadworthy at all times. As part of your regular maintenance routine, changing the lubricating fluids and oil in the motorcycle’s engine, transmission and primary drive can prevent premature wear and heat buildup. Although the thought of undertaking this task may seem difficult for the less-than-mechanically-skilled Road King owner, the process is straightforward and can be done fairly quickly after the first or second attempt.
1. Place your Road King on a stand or lift. In order for the fluids to drain properly, the motorcycle must be upright during the process. If you do not have a motorcycle stand, click on the “DIY Motorcycle Lift” link in the Resource section to learn about make one using easily obtainable items.
2. Place an oil pan beneath the engine oil drain plug. The plug is under the motor and just in front of the oil sump. Remove the plug, using a socket wrench, and allow the oil to drain. Remove the drain plug’s O-ring and replace it with a fresh O-ring. Wipe the tip of the drain plug clean with a shop towel and reinstall it into the motor once the oil has drained completely.
3. Move your oil pan beneath the oil filter. Using a strap- or cap-style filter wrench, unscrew the oil filter from the motor and allow any remaining oil to drain into the oil pan. Fill a new oil filter with oil, and spread a coating of oil around its mating surface. Screw the new oil filter onto the motor by hand until it is seated against the motor. Tighten the filter an additional half to two-thirds of a turn, by hand, to secure it.
4. Add up to 3 quarts of fresh engine oil into the oil tank. Use a funnel to prevent the oil from spilling. Once the oil tank is filled, remove the funnel and wipe it clean with a shop towel. Replace the oil tank’s filler cap.
5. Move the oil pan beneath the transmission and remove the transmission drain plug with a socket wrench. Allow the transmission fluid to drain completely. Remove the drain plug’s O-ring and replace it with a new O-ring. Wipe the drain plug with a shop towel to remove any debris before reinstalling it onto the transmission.
6. Add up to 1 quart of fresh transmission fluid into the transmission. Use a funnel to prevent the fluid from spilling. Once the transmission fluid is filled, remove the funnel and wipe it clean with a shop towel. Replace the transmission’s filler cap.
7. Remove the round derby cover from the outer primary cover using an Allen wrench. Set the derby cover and its gasket aside. Place your oil pan directly beneath the derby cover. The primary drain plug is located below the derby cover; remove it with an Allen wrench and allow the fluid to drain completely. Replace the drain plug’s O-ring and wipe the plug clean with a shop towel before reinstalling it onto the primary.
8. Pour up to 1 quart of fresh primary fluid into the primary through the derby cover’s port. Once filled, the primary fluid’s level should be at the base of the clutch assembly. Reattach the derby cover and its gasket, tightening the bolts with a socket wrench.