Well first off turning 3 - 4 times in 4 wheel drive on pavement will make it feel like your hopping. If you’re in snow or mud it will still feel a little choppy because of the extreme turn. You should never turn hard in 4 wheel drive on dry or even wet pavement, you'll twist the axles and snap something if not really mess up your tires too.
Now if you need a real good mechanic, I'm in North Jersey, Wharton, there's a really good shop around the corner from me Automotive Magic. The owner's name is Shawn and his number is 973-366-3777. Real good guy and honest to boot. I was recommended to him from a real close family member that worked for an auto parts store and dealt with him a lot. I've been going to him for about 2 1/2 years now.
PS He drives a 99 Lighting custom built motor by Johnny Lighting (Johnny's Truck 8.49 second 1/4 mile 165.5MPH )