Alright I have a 2008 3500hd. When I let off the gas it makes a awful roar. Acts if I am hitting the brake. I noticed it started leaking oil around the driveshaft today as well. When I hit the throttle it all goes away. When you are getting close to stopping it acts if it is hanging on...

:help Changed my rear diff fluid today. Bought the truck 3 months ago and was concerned about the rear diff because that's what went on my 98 K1500($750 repair) before I stopped driving it, so I am now paranoid by differentials. Replaced with Lucas 75W-90 synthetic(Hopefully I do not regret...