The Shovelhead engine was introduced by Harley-Davidson in 1966 and was used until 1984, when it was replaced by the Evolution engine. The engine boasted a 1,340 cc displacement and Harley-Davidson’s classic 45-degree V-twin cylinder arrangement. The Shovelhead engine, as produced up to 1981, relied on an in-oil tank filter element to keep debris from entering the engine. While the process of changing the engine oil and filter differs slightly from later Shovelhead models, which use a spin-on automotive-type filter, nearly any Shovelhead owner can complete the job with little difficulty.
1. Park the motorcycle in a well-ventilated area on its side stand. Start the engine and let it idle in place for three minutes, then stop the engine. Let the engine cool for another 10 minutes.
2. Remove the rider’s seat from the motorcycle using a flat-head screwdriver.
3. Unscrew the oil tank cap from the left side of the motorcycle, located directly below the rider’s seat. Loosen the oil drain plug, located at the bottom rear corner of the oil tank, using a socket wrench. Hold a funnel below the oil drain plug, placing the end of the funnel into a 1-gallon plastic jug. Unscrew the oil drain plug by hand and allow the oil tank to empty.
4. Wipe the oil tank drain hole clean with a shop towel, then screw the drain plug into place by hand. Tighten the drain plug to 18 foot-pounds using a torque wrench.
5. Unscrew the oil filter cap from the top of the oil tank, then pull out the oil filter assembly. Remove the D-shaped ring from the top of the oil filter assembly using pliers. Pull the upper washer off of the oil filter, then pull the oil filter element out of the outer filter housing.
6. Soak the oil filter element in a parts cleaning solvent until the element is free of debris and oil. Squeeze out the excess solvent, but do not wring it to avoid damaging the element.
7. Reinsert the element into the oil filter. Place the upper washer over the element and reattach the D-clip. Push the oil filter assembly into the oil tank and screw the oil filter cap into place.
8. Fill the oil tank with four quarts of 20W-50 Type-SF engine oil. Screw the oil tank cap into place.
9. Start the engine and let it idle in place for three minutes to circulate oil through the engine. Stop the engine and let the oil settle for another 10 minutes. Lift the motorcycle off of its side stand and into a level, upright position. Check the oil level by looking into the oil tank through its filler neck. Ideally, the oil must be 1 inch below the bottom of the filler neck. Add oil as needed to raise the oil level, or remove oil with a hand pump to lower the oil level. Screw the oil cap into place and lower the motorcycle onto its side stand.
10. Reinstall the rider’s seat.