The son did a little off-roading Saturday night. Got out to unlock the hubs, with no problem. He went to the carwash to hose off the mud and discovered that one of the front hubs was missing. After further inspection he discovered the adjusting nut was cracked and metal shavings were present. This is a 1990 Bronco with factory manual hubs. We are replacing the hubs with Warn premium and any other parts that looked trashed after he digs into it. What is your learned opinion as to what could have caused this? He did have the gears redone about 4 months ago. I suspect they didn't reassemble that side correctly.