I have a 99 gmc sierra with 4 wheel drive. I have notice when I turn it on. I can drive straight just fine. But when I turn at any speed or any angle, the truck begins to lock up and stop.

I replace the front differential thinking it was that but it still does it. Any help? Thank you!

 

it could be the rear differential , or transfer case binding up. Take off diff cover and inspect. Drain TC fluid and look for metal.

 

I wonder if the OP has a stick-shift? My K-1500 will bounce and jump all over making a turn on the pavement in 4-high but the motor never died but I don't use it. I use 4-low to back out of some parking spots so I don't wear out the clutch, and at super low reverse speed it doesn't jump around. I think you are correct, all that said. Likely a bad T-C.

 

hopping around on the pavement in 4WD like that can't be good for your driveline. I'd rather put a bit of wear on the clutch.

 

I've only had that happen when off-road going to on-road it its not icey. Then I put it 2-high. At 4-low backing up, it just makes it easier in a packed parking lot and it doest jump around once I'm basically idling it out. I stop backing it and go back to 2-high.