1982 Cj7 Locking Hub Issues

Writing this for a friend. A couple weeks ago he was driving around his hunting club at slow speeds and at almost the same time the front u-joint and one of the front locking hubs “exploded “. He took it to a mechanic And had these things replaced. The next weekend his Dad drove it around both days and everything seemed fine. Last weekend they were driving and it seemed that 4x4 wasn’t working, over the phone I tried to confirm that everything was engaged properly and sounds like it was so I told him to try unlocking the hubs and roll it a bit then try again. Well, I guess one of the front hubs would only turn slightly from 4x4 and not all the way to 4x2. Now, I know that the 5 bolt hubs aren’t as stout as the 6 bolt but these are pretty mild dirt roads and brand new hubs! Anyone have any idea what would cause these failures? Seems to me that something has to be going on with the xfer case or the diff. Any input would be appreciated!

 

How are the bearings in the spindle? If the axle end is flopping around it could make the hubs not work.

 

Was he driving it around in 4 wheel drive on hard surfaces with hubs locked in? If so, there's your problem. When people do that driveline windup happens, puts everything in tension with no give, and something has to give. Even gravel can cause this.