i just bought a 2004 CTD 2500 and when it shifts into overdrive going anywhere fron 55mph and up the exhaust changes its tone it gets really deep, espesially on the interstate, just wondering if this was normal?

also i was wondering, how do i know if i have to HO or not?
thanks
adam

 

More then likely yes.BUT I think(oops)LOL that maybe a TSB on driveshaft etc.concerning rubber sleeve"dampner" or a updated shaft with dampner already on it? For noise reduction? Might be off base on that but think I've read something like that.