Harley-Davidson® Transmission Oil Change Instructions

Use these simple Harley-Davidson transmission oil change instructions to change transmission oil on your bike. Here's how to do it.

May 25, 2021

For maximum wear protection and shift performance, it’s important to periodically change transmission oil in your motorcycle. Otherwise, the fluid can breakdown and fail to protect gears and bearings, not to mention interfere with the smooth, crisp shifts you want when riding. Here, we provide Harley-Davidson transmission oil change instructions using a 2014 Softtail Fat Boy Lo.

Watch: Harley-Davidson Transmission Oil Change Instructions

Tools you need

  • 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 plug 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.
Harley Davidson transmission oil change instructions.
  • While the transmission fluid is draining, clean the drain plug. Make sure to remove all the debris and check the plug for damage.

Install a new O-ring

  • 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.
Harley Davidson transmission oil change instructions.
  • 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.
Harley Davidson transmission oil change instructions.
  • 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.

There you have it – Harley-Davidson transmission oil change instructions for your next oil change. Make sure you dispose of the used oil properly.

Check out our posts on how to change oil on a Harley-Davidson and how to change primary fluid on a Harley.

Harley-Davidson owns the trademark rights to Harley-Davidson and the motorcycle models listed. No affiliation or endorsement claim, express or implied, is made by their use.