Change all three oil types every 2,500 miles to prevent mechanical failures on the road.
Harley-Davidson’s 2006 Heritage Softail is powered a three-part engine, transmission and primary drive system. Oil changes are required in 2,500-mile intervals to keep the motorcycle in a healthy state of tune. While most motorcycle oil changes are as as simple as emptying and refilling the engine’s oil supply, the primary drive and transmission oils must also be changed at the same time. Although this does add some extra work to the job, it can be completed by most Softail owners in a reasonable amount of time.
1. Warm your Heritage Softail’s oil supply. Start the motorcycle and take it for a short, five-minute ride, then park the motorcycle on its side stand and let it cool for another 10 minutes.
2. Place the Heritage Softail on a stand to hold it in an upright, level position. Unscrew the oil tank filler cap by hand. Unscrew the transmission filler cap, located on the right side of the transmission, facing toward the front of the motorcycle, using a 3/8-inch Allen wrench.
3. Unscrew the engine oil drain plug from the bottom of the engine, located along a cross-member that runs between the lower frame rails near the swingarm, using a socket wrench and a 5/8-inch socket. Drain the engine oil into a drain pan.
4. Slip the sealing washer off of the engine oil drain plug, then wipe the plug’s tip clean with a shop towel. Place a new sealing washer on the drain plug, then screw the drain plug into the engine by hand. Tighten the drain plug to 20 foot-pounds, using a torque wrench and a 5/8-inch socket.
5. Unscrew the cylinder-shaped oil filter from the oil pump, located on the front of the engine, using a strap wrench. Drop the oil filter into your drain pan and allow any oil remaining in the oil pump to drain. Clean the oil pump and its mounting flange with a shop towel and a parts-cleaning spray.
6. Pour 4 ozs. of 20W-50 motorcycle-grade engine oil into the new oil filter. Spread a light coat of oil around the oil filter’s threads and mounting surface. Screw the oil filter onto the oil pump by hand until it is seated snugly. Tighten the filter an additional 1/4-turn to lock the filter in place. Do not use tools to tighten the oil filter.
7. Fill the engine oil tank, located below the right side of the rider’s seat, with 2.6 qts. of 20W-50 motorcycle-grade engine oil. Screw the oil tank filler cap into place by hand.
8. Unscrew the transmission oil drain plug from the bottom of the transmission assembly, located between the pair of shock absorbers mounted on the bottom of the motorcycle, using a socket wrench and a 5/8-inch socket. Drain the transmission oil into your drain pan.
9. Slip the sealing washer off of the transmission oil drain plug, then wipe the plug’s tip clean with a shop towel. Place a new sealing washer on the drain plug, then screw the drain plug into the transmission assembly by hand. Tighten the drain plug to 20 foot-pounds, using a torque wrench and a 5/8-inch socket.
10. Fill the transmission assembly with 1 qt. of Harley-Davidson transmission fluid or an 85/-140 API GL5 gear oil. Screw the transmission filler cap into place, using a 3/8-inch Allen wrench.
11. Unscrew the round clutch inspection cover bolts from the outer primary drive cover, located on the left side of the engine, using a Torx T-27 screwdriver. Pull the clutch inspection cover and gasket away from the primary cover to reveal the clutch assembly.
12. Unscrew the primary oil drain plug, located directly below the clutch inspection cover port, using a Torx T-40 screwdriver. Drain the primary oil into your drain pan.
13. Slip the O-ring off of the primary oil drain plug and replace it with a new O-ring. Screw the drain plug into the primary cover, using a Torx T-40 screwdriver. Tighten the drain plug to 6 foot-pounds, using a torque wrench and a Torx T-40 socket.
14. Fill the primary chaincase with one quart of Harley-Davidson Primary Chaincase Fluid or Type D or F automotive automatic transmission fluid. The fluid level should be even with the lower portion of the clutch assembly, visible through the clutch inspection port.
15. Reinstall the clutch inspection cover and gasket, using a Torx T-27 screwdriver. Tighten the clutch inspection cover mounting bolts to 10 foot-pounds, using a torque wrench and Torx T-27 socket.