Harley Davidson Motorcycle Transmission Fluid Change

For this demonstration, we’re using a Harley-Davidson Softail, specifically a 2014 Fat Boy Lo.

Tools you need to change motorcycle transmission fluid

• Drain pan
• New drain-plug O-ring
• 5/8-inch socket with a socket wrench
• Torque wrench
• 3-inch extension
• 3/8-inch ball-end Allen wrench
• Funnel
• AMSOIL V-Twin Transmission Fluid

Locate the transmission drain plug, which can be a bit tricky. First, locate the two shock absorbers. The drain plus is located between the shock absorbers, underneath the transmission.
Use the ratchet, 3-inch extension and 5/8-inch socket to remove it. Once it’s loose, finish removing the drain plug by hand to prevent it from falling into the drain pan.
While the transmission fluid is draining, clean the drain plug. Make sure to remove all the debris and check the plug for damage. Slide the new O-ring onto the transmission plug and run it all the way to the bottom. Re-install the drain plug. Snug it up by hand, then use the torque wrench set at 14-21 foot-pounds torque to tighten it.

Fill the transmission with fluid

Use the 3/8-inch ball-end Allen wrench to remove the transmission cover and dipstick. Use a long-necked funnel to install the transmission fluid. Be careful not to overfill the transmission. Check your owner’s manual or the AMSOIL Product Guide for the correct fluid capacity. Remember to stop and check the site gauge on the bottle to prevent adding too much fluid.
Some bikes require checking transmission fluid when it’s on the kickstand. Check your owner’s manual for specific instructions for your bike, then pull the dipstick and verify the fluid level.