Does your truck have ADD or was it manual hubs from the factory? The front end sliding gear on ADD is on the left side and could have broken.
Can you move the CV joint on the back of the hubs or at the diff? I'm talking about side-to-side, not in and out?
Have you tried turning the half shafts with the hubs unlocked? Should be easy to turn and the opposite side should turn backward or the front driveshaft might turn. If you lock the t-case in 4WD, the other side will definitely turn. There should be no binding and you probably will feel the ring gear turning the pinion.
I'm going to guess that the end of your axle sheared or your hub shattered and is jammed in the spindle. Were the hubs warm when you locked in the hubs or was the grease cold still?
'91 Pickup - Imelda
'08 Tacoma TRD - Donna