Changing your Road King’s oil and fluids regularly will ensure years of enjoyment.
Regular fluid changes are a fundamental part of keeping your Harley-Davidson Road King roadworthy. Unlike the motors used by other manufacturers, Harley-Davidson employs three separate fluids to lubricate the Road King‘s motor, primary drive and transmission systems. This can easily confuse a new Harley rider, who may be used to changing a single oil type.
1. Place your oil pan beneath the motor oil drain plug. The drain plug is located on the right side of the motor and to the rear of the frame. Remove the drain plug with a Torx socket and replace the plug’s o-ring. Allow the oil to drain completely before reinstalling the drain plug.
2. Remove the oil filter with an oil filter wrench and discard it. Fill the new oil filter with fresh oil and spread a thin coat of oil around the filter’s inner mating surface. Screw the filter into place on the motor by hand and wipe away any spilled oil with a shop towel.
3. Open the oil tank’s filler cap and pour up to 3 qt. of fresh motor oil into the tank. Replace the filler cap and wipe away any spilled oil.
4. Place your drain pan under the primary cover drain plug. The drain plug is located directly under the round derby cover on the outer primary cover. Remove the drain plug with a Torx socket and replace the drain plug’s o-ring. Allow the primary fluid to drain and replace the drain plug.
5. Remove the derby cover bolts and pull the cover off the outer primary cover. Pour up to 1 qt. of primary fluid in through the derby cover port, filling the primary until the fluid is touching the lower edge of the clutch diaphragm spring housed within the primary.
6. Reinstall the derby cover and wipe away any spilled fluid.
7. Place your drain pan directly under transmission and remove the drain plug. Replace the drain plug o-ring. Allow the fluid to drain completely and reinstall the drain plug.
8. Remove the transmission’s filler cap and add up to 1 qt. of transmission fluid.
9. Replace the filler cap and wipe away any spilled fluid.