2002 express 3500 motor home noise under motor home sounds like maybe ring& pinion just bought one trip , how best way to check make noise mid range on an off gas let up slight an noise may stop till you start to go , i was hoping it was a removeable punpkin , where is the best an cheapest place to get it fixed, at 80 changing the hold rear end might be too much??? this is my 4th motor home an i do most of my own work, ps can the rear end be reset up with out changing the ring an pinion???