The only other 4wd's I've owned was an 89 yota with open diff in front, and a 2000 scab. Never thought to check on the 2000 Fors, but on the yota (with the tran case in 2hi and the hubs free), the front drive shaft was stationary when in motion. Now I've got an 06 FX4 with what I am assuming is an open diff in the front. When I was installing my level kit lastnight, I noticed the driveshaft spinning when I rotated the wheel...only one wheel was off the ground, so I'm not sure if that makes a difference. Since I've never looked underneath the truck while driving, I don't know if it's stationary while in 2wd or not. The only reason I would care is relative to the extra wear and tear, stationary v. always rotating.

Can someone clear this up?

 

The front hubs lock are vacuum operated. The default function (no vacuum) is the hubs are locked. With the engine running and vacuum applied, the hubs unlock. Sounds backwards, but that is the way it was designed.

 

Ah, I see...thanks!