Older Harley-Davidson motorcycles (1990 and older) use a chain for the final drive. Some newer models also use a belt drive but you can still get a Harley with an optional chain drive. As a chain gets older, it stretches. Therefore, you must routinely adjust the chain on your Harley to keep it tight on the rear sprocket.
Loosen the axle nuts on both sides of the rear tire with an adjustable wrench. Do not remove the nuts from the axle.
Locate the chain adjustment bolts. On the right side of the Harley, the bolt is located to the right of the axle nut. On the left side of the Harley, the bolt is located on the left side of the axle nut. Both bolts are perpendicular to the axle nut and both have either a hex head bolt or an Allen head. This depends on the model of Harley you own.
Turn the adjuster on the left side of the motorcycle one complete rotation then duplicate the process on the right side. Always make sure you turn each bolt equal distances to ensure the rear wheel stays straight.
Check the chain tension by pushing down on the top center of the chain. If you can push the chain downward more than a 1/2-inch, repeat step three until the chain has less than a 1/2-inch play in it.
Tighten each axle nut with the adjustable wrench.
