truck: 2001 4wd ram 1500

Well, today I go to pull out of my parking spot after it sitting there for no more 15 minutes, and I start to pull out of my spot, get about 2' (or so) out of my original position, then the truck suddenly stops like I hit something. But of course I didn't hit anything.
So I pull forward, then the same thing happens again after about 2'.

So basically, it goes into gear fine and all, but after about 2' or so, it stops suddenly and won't move in that direction any further. Any ideas?

I'm kind of guessing that perhaps I stipped out (or have a broken tooth or something) on the front ring/pinion. I'm guessing this since the length of movement is roughly the circumfernce of the tires. I also think it could be the front since the first time this happened, it happened at a decent speed, and the rear tires didn't break traction like you'd expect if it was the rear end which siezed up. Also, my truck would be the third 2nd gen ram at my school to have the front diff go within the past month, lol.
So right now, it's sitting in the parking lot of the car wash, and I'm going to head back out there later tonight to see if anything has changed, and perhaps call a tow truck if necessary.
I don't think it's the transmission or the transfer case because it goes into and out of gear fine, and then even when I put both the transmission and transfer case in neutral, I can't push the truck past the one point.

Although, could it be the auto-locking hubs? Or does the truck even have auto-locking hubs?

 

Well, I managed to get the truck back home, but only after putting it in OD lock-out. I got home, checked it for codes, but it didn't throw any. I was also able to now move it with OD on.
Any ideas? I did get a hypertech recently, but that shouldn't cause that...

 

it sounds like its binding up somewhere i would first try to jack it up and spin the tires in gear and out of gear and with locks on and off see how that goes if it does it only in gear with od off i would take off drive shafts and see if the tailshaft spins if it doesnt then youve tracked it to tranny/transfer problems

 

Well, I removed the hypertech programming earlier this week, and it appears to have fixed it. It locked up on me again before removing the programming, and I'm on my 4th day w/o the programming and no problems...besides the truck feeling slower.[:@] But still, that doesn't make any sense at all...that shouldn't at all cause any problems whatsoever!

There is a local trans. shop here that'll do a free inspection for me, so I think I'll take it in sometime next week just to be sure.

 

parking sprag not releasing in transmission/sliding in while in motion, ring and pinion problems, tranfer case problems.
Thats about all that could cause this problem.
Its gotta be something hard.

 

Well, I don't think there's any ring/pinion problems considering there's no excessive vibration while driving or anything.
Transfer case does sound like a candidate because when you put the T-case in neutral, it's supposed to disconnect the driveshafts from the axles, right? When I put it in N, I still couldn't even push the truck.

It locked up again last night as I was backing out of my friend's driveway. I got further this time. And all I had to do to get it going again was reverse, then put it back into drive. This was after removing the hypertech programming.