In about the last 300 miles the t-case on my 84 fj60 w/ 700r4 has gotten noisy (atleast more than normal) it has the typical whine only a little louder. what really caught my attention is that there is a pretty loud chatter (louder sometimes than others) right between accelleration & decelleration at freeway speed. I drained the fluid about 150 miles ago & it was fairly glittery. Im going to check the fluid again tonight. to me it sound like rebuild time so is there any way to tell what size idler shaft I have just by looking at the case? I suspect it is the earlier smaller one but want to know for sure to avoid down time. also how can you tell if the gears need replacing?

Thanks!!