Can anybody tell me if the stock mufflers need to be removed to change out the rear tire or adjust the centering of the rear wheel on a 2014 or newer XL1200C ?

 

You need a factory service manual, which will answer that question, along with the others that will naturally follow! Yes you will need to remove the rear muffler, to withdraw the axle. You could refit that from the other side, so next time you don't have to. Centering the wheel can be done without removing the muffler.

I haven't tried it, but you may be able to remove the wheel by disconnecting the rear shocks and jacking the bike up so the axle can be withdrawn from underneath the rear muffler.

 

Easy peasy without the muffler.

 

When you're ready to reinstall the new tire and wheel, turn the axle around and reinstall it from the other (left) side of the bike. The axle nut will be on the muffler side and you'll be able to pull it the next time without the exhaust being in the way.

** Just be sure and reinstall (or replace with new) the safety cotter pin on the axle nut.

 

This is one thing Harley seems to ignore but it's a logical change. It makes life so much easier.

 

It's kind.of a safety engineered HD choice. Same with aircraft, install the bolt so it can't slip all the way out if the nut comes loose.

 

The current set-up is better, they used to come with a split pin through a hole in the axle, which needed to be replaced frequently.