Alright folks, I have symptoms the same as Herb here: <https://forum.ih8mud.com/showthread.php?t=138449> A clunking and obvious "rubbing/grinding" sound, but only sometimes. Other times it is quiet and no problem. So I took off the driveshaft and everything up to and including the speedo housing to inspect for anything wrong. Also to install my mudrak housing. (which work AMAZING by the way) Nothing there. So then I took off the diff cover and found not to much(first picture). No metal fragments, no unusual wear anywhere. However, some slight wear is noticed in the second and third pictures, on the most central piece (don't know it's correct name) in the same place where Herb had a nice wear pattern. In addition, the stake nut on the flange where the driveshaft bolts looks to be ok, and doesn't look like it has moved or loosened up. (fourth picture) Additional info - I did have to swap the flanges when i put a 4 speed tranny/transfer in, so the nut came off, flange swap, nut back on, but nothing was moved or opened up. Also did a rear disc swap, so axle shafts out and back in, no issues there. Lastly, I have been driving this thing for about 300 miles with no problems following my frame off build, then this noise and such started. So.... 1) Do i need a new third? 2) If not, what actually is wrong and how do I fix this? (vague, but you all are pros) 3) This axle (from a 73' 40) has 3.73 gears, right? On a lighter note, please give me a reason to pull the third so I can spring-over it! (not really) Thank you all in advance!