So I did a lot of readin' and had some hopes that maybe this was just a "noisy" NV4500 since some of them just clatter around. It's not like it's a very refined trans after all. Though it also might be that 4 qts of the specified lubricant might not be enough with the PTO filter I installed. So added another quart, set the clutch fork to .030" and started it up again.
Same clatter...
Man oh man.
I put a screwdriver to it to diagnose it and it's definitely the transmission. I ran it through 1st and 2nd gear (on jacks) and the problem sounds just as bad when under load.
I'm pretty sure I "got took" by an FleaBay trans shop. It sounds the input bearing, idler shaft, or counter shaft bearings are trashed. Guess I'm back to square one on this thing...I'm glad I'm going on leave tomorrow. Going to do some dove hunting in Alabama and then head to the lake. Much needed R&R. I might make a bad decision if I was around all week, haha! This is what it's all about!!!