I have a 1994 ford ranger 4wd and have had trouble with the 4wd. I had the stock auto locking hubs replaced 8 months ago with warn manual locking hubs. They worked great until last week when the drivers side hub exploded. I shifted from 4wd to 2wd and had the hubs locked still. While I was driving the driver's side hub exploded and some parts went flying. I had the hub replaced but now both front wheels spin freely in 2wd with hubs unlocked but if i lock the hubs the drivers side wheel wont turn. Is there a problem with the front differential or transfer case?

 

What happens if you have the hubs unlocked and shift into 4wd? If the t-case is working properly you should see the front drive shaft turn just fine. That would eliminate the transfer case from the equation and shouldn't hurt anything (at least worse then it might already be) based on what you are saying.

 

Haven't tried that, I had it up on a lift and with both hubs locked I turned the passenger wheel and the drivers side turned the opposite way. When I was off the lift in 2wd with both hubs locked and tried driving the driver side feels stuck and wont turn.
If I switch to 4wd with hubs unlocked how can I see the drive shaft turning?