Check The Transmission Fluid On A Nightster

The Harley-Davidson Nightster was introduced in 2007 as part of the Sportster line of bikes, which has been produced by the company since 1957. Checking the transmission fluid is part of the regular maintenance you should do on the bike. Ideally, you should check the trans fluid every one to two weeks when checking the other fluids in the motorcycle. The transmission fluid keeps the gears running smoothly and the engine optimized. Neglecting this maintenance can lead to costly engine damage. Fortunately, checking the transmission fluid only takes a few minutes.


1. Run the bike for five to 10 minutes and shift through all the gears to warm up the engine. Place the Nightster in a motorcycle stand on level ground.

2. Remove the 10 screws on the engine casing at the front of the bike with the Phillips screwdriver. Lay the casing and screws to the side in a safe place.

3. Pull out the dipstick from the transmission fluid tank. Wipe off the stick with the rag. Check the appearance of the fluid; it should be a translucent red color. If the fluid is dark or opaque, it’s time for a transmission fluid change.

4. Put the dipstick back into the tank and pull it out again. Read the level of fluid on the stick. The level should be at least halfway between the minimum and maximum lines. If it is less than halfway between the two lines, place the funnel into the tank and pour in small amounts of fluid at a time, checking the levels after each filling. Replace the dipstick when finished filling.

5. Secure the casing on the bike with the screws.