Help! I fly up to Arkansas to pick up my new F350 7.3 Dually (they are getting hard to find in 7.3) I sign paper work and am about 40 miles outside of town when I pull over to get a drink upon taking off i have a horable pop coming from rear end its so bad that you can see the <a href="http://service.bfast.com/bfast/click?bfmid=37919709&siteid=39251846">tires </a>jump when it pops. only does it at slow speeds forwards and reverse. Take it back to dealer (to make a long BAD story short) They say its normal and will go away by 9000 miles. Says that cluthes or something is not seating! Dont see how this could possible be good . Has anyone else ran into this?

 

I had a similar popping sound coming from my rear diff (noticed it a lot when driving next to a concrete barrier at highway speeds though). I have a 2000 F350 PSD DRW 4x4 with 4.10s and the factory limited slip in the rear. I can't recall the rearend actually hopping (maybe due to the weight of the dually), but it did pop when turning as well in a straight line. I took it back to the dealer at about 15,000 miles and they replaced the LS and I believe the gears as well. I have not really noticed anything or sounds that concern me since. I now have about 90,000 miles with no further problems.
Hope this helps,