No left turn in 4hi/4lo

Specs: 91 5.5 lift, D30 w/OAT, cross over steering, front ARB locker , 4:56 33x12.50.

So today out at corral canyon (local spot) I aired down to 10-12 psi and fit the trail.. First obstacle i could not for the life of me get it to turn left. Even when in N and reving the gas. Passenger tire was under some load but not to crazy. So i called it quits and headed back. In 2wd you would never know the difference. Like it never happened... So i have a new PS pump and Durango box being delivered tomorrow. Any thoughts or suggestions would help. ooh PS pump and box are stock. gear box looks to be original.

I've had that issue. Ended up being the TRansfer case.
I'd put it in 4wd and either left or right turns would be nearly impossible to turn all the way and it's a bumpy SLOW turn.... Kind of a feeling of the front end about to break. Also, the lever would get stuck on 4wd at times.