Not exactly sure to be honest...i do know from a fellow long travel dakota that he has had a problem with these bolts braking and told me to make sure to keep an eye on them. I will get a pic of the one in alil bit. Looks like it may have come loose and just started to move around but they were extremely tight when I originally removed them

 

Well it's kinda related, my 99 the caliper was hanging up and noticed, there were grooves, where the brake pads rested, i grinded a lil bit off off spindle and haven't had a problem with brake pads not releasing, didnt see if your truck was a 2 or 4 wheel drive, possible cv shaft??

 

This is what EricBing is talking about.

You can develop grooves in the spindle these can cause your brake pads to snag in the grooves and cause binding just use a file and try to smooth out the grooves but dont take too much metal off the spindle.

 

yes and be very careful if u use a grinder, LOL love power tools, oh and that caused me many a headache even after new calipers, rotor, brake pads, problem was right in front of me, sometime we miss the obvious