I can not improve on Burfurd's answer.. I don't know about the 4x4 however.. I do know the rear wheel drive (2wheel drive) models you need a drive shaft disconnect from RemcoTowing.
So you understand.. With the drive shaft disconnect..
It is the same as if you crawled under and removed the drive shaft when you tow. NO connection between the transmission and wheels.. Also makes the ride hard to drive off with
No miles rack up on the odometer either.. All around best soultion to towing.
Do, add an aux braking system like the US-Gear Unified Brake Decelarator or the Invisi-Brake system (I think that's Roadmaster)