My wife was out of town hauling horses and the Dana rear end in her 99 2500 4x4 started leaking oil out of the front input shaft seal. She had the seal and oil replaced at a "quick lube type place" they said there was some twine or string wrapped around the shaft that may have caused the seal to fail but the truck has 90,000+ miles on it so it may have just worn out. She doesnt know how long the seal was leaking before she noticed it but most of the oil was gone and what was left was in bad shape. after the repair she drove the truck home several hundred miles. The seal is dripping oil in the driveway right now... possibly the shaft may have wear or the seal was not installed properly and I am considering doing a total rearend rebuild(important bearings and or seals that may have excessive wear) and the installation of an aftermarket diff cover while I'm at it, I am looking for advice on how to go about this repair myself I have done most type's of automotive repairs on my own cars over the years but never rebuilt a rearend. I am doing searches right now to try and find info but have yet to find any how to's for this type of repair. Also I am missing the data plate off the rear(lube shop lost it) so I don't know exacly what rear I have... I am assuming it is a Dana 80 with a tracloc,I am going to need to know for sure so I can order parts today if I can. Thanks for reading this so far and if you have any info for me please take the time to help as I need to get this fixed in the next couple of days and I would like to do the work myself .