Front End Grinding When Spinning

[909]

1995, 1500, elec actuator (for the first time the thermal might've saved a headache)
I went and engaged the 4wd before I was completely stopped today and everytime I hit the gas it would grind real bad. I tried it three times and it seemed that the grinding wasn't real bad until it started to spin.
Exact same senerio as here http://67-72chevytrucks.com/vboard/s...d.php?t=387246 but the OP isn't active anymore and never came back to give us a solution.
I'm trying to figure out what exactly is stripped or broken.