I have a 2005 HD, and it just started making a howling noise when the vehicle is being driven. I have taken it in to be serviced and they can't find anything wrong. The noise is intermittent, not all the time and it comes from the rear. Heard during gear changes (automatic) and when starting from a stop. No pattern to the noise, just random. Sounds like it is coming from the rear. Any ideas??

Intermitent problems are a pain in the ass to diagnose cause it makes you look like an ifiot when you take it in and it is not making the niose lol. At least being an 05 you should still have warrenty left on it, it may be one of those problems that you have to wait for it to get worse before then will either find it or do something about it.