dana/spicer 44

97 dodge ram 1500 4x4 is the truck.Vibration in the front dana/spicer 44 when the 4 wheel is engaged led me to tear it down. The sign I found that would cause this was on the spider shaft .aka pinion shaft. What I seen was where the shaft mates to the spider gears was rub/grind marks like the metal got hot and smeared. Ok so what would cause this the only thing I can figure is the intermediate axle shaft nosed thru the side gear put pressure on that shaft. But how can that happen because I found no broken pieces. Dose this intermediate shaft float in there or was there something that kept it from running into the pinion shaft. What I don’t want to do is replace the spider gears and shaft only to have it break again because I missed somthing  

Once something fails it tares stuff apart. Those pieces can go anywhere and everywhere and tare the rest up. It really tuff to diagnose a problem over the Internet. Just take a close look at all the parts.