Differential Leak
How long ago did you have your truck regeared? It might still be covered by the warranty from that since I assume they replaced the seal then. A lot of shops have 1 year/10k mile warranties on stuff so if your not past the warranty it might cost you nothing but time.
I replaced my pinion seal yesterday using a Haynes manual as a guide. After talking to a few knowledgable folks, I realized that I could have and would have done a lot of damage to the rear end without Haynes help. Now I just cross my fingers and hope for the best as we get ready for our 1200 mile trip to Talladega for the races pulling a camper!! If I had it to do again, I'd have waited until we got back. Wish us luck. I've always thought that God looks out for fools and babies. There will be both on this trip.



