was riding it down the street and hear a squeak and a pop come from the front end area then it bows up and stops in the middle of the road and wont move forward anymore the rear end tries to push the front when throttle is given but front end wont pull just makes a popping noise. if i jack the front end up and spin the front tires the front axles turns fine no issues the front drive shaft does not spin when i do this though. as far as moving in reverse it backs up just fine no pops or squeaks it moves like it should until you shift back into high range and 1st gear then it does like i mentioned before. what could be wrong with it?

 

Sounds like the front differential is broken.

Maybe drain the oil and look for chunks?