I recently (less than 3k miles) replaced the u joints in the driveshafts and everything still looks and feels great...
I was concerned about the NP because I ran it without fluid for a little bit.
Oh, come on now, you know the routine. You can't leave stuff like that out of the conversation! At least not and still expect an accurate answer.
The bit about the u-joints is important, but the other bit about running the transfer case dry is a critical bit of intel.
So how long is a "little bit" and was it ever in 4wd during that time that you know of?
That said, no whines or engagement issues and I do think it's fine after more testing.
This could be a good thing. Might have dodged that bullet for now. Or not...
The very large main bearings might live without lube, or might actually be dead and dying but not make noise under all conditions. My 3-speed didn't make any unusual noises until the moment I heard the popping and ringing sound of ball bearings shooting around the case.
U-joints can go bad quickly just like a lot of other modern parts. But for the most part, they're pretty good still. So you might be ok there.
But did you check (and more importantly, lubricate) the centering yoke? I assume so, but wanted to make sure because those things can create some very inconsistent symptoms when they're going out.
I kind of hope it's the driveshaft because it's usually easier to fix. But if you have to replace it, or the centering yoke of the CV head, it might be as expensive as rebuilding the entire transfer case (if you do it yourself) but not as expensive as something in the rear end.
Anyway, as said those main bearings in the transfer case are very robust. But if they're 45 years old, and ran long enough without lubrication (mainly the upper output bearing I think) that might have done some damage after all.
Good luck.
Paul
