Replacing the muffler or dual mufflers on a 2008 Harley-Davidson, whether the Nightster, the Ultra Classic, or another model, is simple straightforward, although the exact method varies by model. The mufflers may corrode over time or break if the motorcycle tips on its side. A cracked or broken muffler may leak exhaust or generate a loud and unpleasant noise. If you wish to install an aftermarket muffler, check that the dimensions of the new muffler fit the chassis before purchasing.
1. Loosen the bolts on the clamp that holds the muffler to the mid-pipe with a socket wrench set.
2. Remove the bolts on the peg bracket that secures the muffler to the body. The peg bracket may be concealed by saddlebags, in which case first remove the bolts holding the saddlebag to the Harley-Davidson and lift off the saddlebags.
3. Remove the bolts completely from the clamp between the muffler and the mid-pipe. Wiggle the muffler back and forth off of the mid-pipe. Squirt WD-40 into the crevice between the overlapping portions of the pipes if the muffler is stuck. Pull the muffler off of the mid-pipe.
4. Slip the new muffler over the mid-pipe. Place the clamp over the overlapping section of the muffler and mid-pipe. Tighten the clamp in place with a torque wrench. Check the manual for the mufflers you bought to see how much torque to apply.
5. Mount the muffler to the peg bracket with the bolt you removed earlier.
6. Repeat Steps 1 through 5 for the second muffler if your bike has dual exhausts.