Grinding noise when I take off sometimes. Feels like the 4wd is half way in or something.
Needs to be looked at by a mechanic. Grinding is bad.
Grinding is frequently followed by a loud bang, and then silence, as the vehicle coasts to a stop.
This is definitely something that needs to be diagnosed by a mechanic.
If you drive on hard clean pavement in 4WD this can happen. 4WD is only for soft or slippery conditions like sand, gravel, dirt, mud, snow, etc. that allow some wheel slip.