[GMTRUCKLOVER]

The "jerking" in 4 high while turning is totally normal.

You say in 4 Low it will barely get above a crawl?? Hmm. 4 Low is simply a lower gear ratio produced through the transfer case, so you definately will not be able to reach any high speeds at all. It's designed for situations where more than normal power is needed. As far as the whining you hear, that is most likely the gears meshing together in the transfer case, also normal in 4 Low. Earlier models had a chain drive and you would not hear any whining from them. LOL.

 

[GMTRUCKLOVER]

No, it should feel the same going straight whether in 4 high or 2 high. In 4 Low it should rev up fast and not GO too fast.

If it feels like something is dragging or that it labors so to speak when it's locked in, then yes, I would definately have it checked out.

Hope this helped!

 

[GMTRUCKLOVER]

I think the "jerking" will depend on how aggressive your tires are. The more aggressive, the more jerky it will be while turning, no matter what surface you are on.