Originally Posted by rekwiat
I wish our tahoe had that!
Are you sure it doesn't? My 2007 Avalanche has a dial for selecting 2wd/4wd/4wd low or auto on the dash board. There is an UNMARKED position to disconnect the drive train. The setting is far right. With key in on position, Turn the dial counterclockwise and it will spring back. Drive train will be disconnected until next start of engine (or key on).
Check your owners manual. Also, when starting, a red symbol like a Z appears on dial momentarily. It is otherwise not visible, unless you have disconnected drive train.
If you try this, remember that disconnecting drive train will render "Park" useless. Be sure to be on level ground, parking brake on, and foot on brake. Or in the case of towing, connect tow bar to RV before doing this.