what do you mean bone dry? exactly how dry is that?

you need to have the diff torn into right away. restoring the fluid level isn't much of a solution. If any of those bearings ran dry for even a 100 yrd trip, things are likely in bad shape and need replacing. and the only way you are going to know how bad is to tear into it. pinion bearings don't take kindly to being run dry, you could have easily damaged one of those and you certainly don't want to lock up a pinion bearing, could be very dangerous!

if this diff was as dry as you implied, don't wait, <img src="/forums/images/graemlins/shame.gif" alt="" /> have it looked at immediately.

-Rob