for the record, I have done Moab twice and been all over Colorado in my 98 and front diff is fine. Just avoid wheel spin as much as possible.
Exactly, the 2 pin was never a problem on the 80 series or the early 100 series. Toyota went to the 4 pin in 2000 because of A-Trac which puts enormous strain on the front diff, which is why you see so many 4 pin failures. Extreme abuse can cause either one to fail. The "weakness" of the 2 pin is one of the great myths on this forum.