ok so i have a 2000 dodge ram 1500 196,000 miles transmission is about 1-2 years old it started 1 month ago when i had to put my truck in 4x4 to back up a dirt hill so i turned my wheels and i heard a loud pop and my front wheels locked up.
so i put it in 2x4 and drove just fine took it to the shop they said it was my wheel joints i had them changed along with my upper/lower ball joints i got it back 2 days ago and tried the 4x4 to see if the issue is resolved.
but now insteads of the popping and locking up it acts like it seizing up and not wanting to move but as soon as i put it in 2x4 it drives normal once again.
any ideas what else it could be?

 

Are you driving on solid ground(pavement/asphalt)? If so that's probably why. 4X4 is to be used in low traction(snow/mud/dirt) not on solid ground. You can damage the transfer case.

 

no it’s not on solid ground it was in loose dirt

 

Take off the rear driveshaft. Unbolt and remove the tail shaft housing from the transfer case. There should be a snap ring on the output shaft against the bearing. If it's still on the shaft, make sure it's actually in the groove. They had a tendency to break or pop out o the groove. Then the out put shaft gets pushed in by the drive shaft until the t-case grenades. The best fix is a Gilly's Transfer Case Saver.

 

Not testing on a hard surface are you? That will really annoy your driveline. But, if on a loose or low-traction surface, and it's binding, then something ain't quite right, and it's time to have a look. Jack it up, (with the truck in 4x4) get both front wheels off the ground, and spin one of 'em. See how it feels, and which way the other tire turns.