I have always had manual transfer cases before. now my f250 had esof 4x4. I noticed when my wife was moving my truck that the front driveshaft turns in 2wd. I swear I remember my manual t-case rigs not doing this. Just trying to figure put what is normal..
The front driveshaft will lazily rotate in 2wd. This is just due to friction in the system. However, it should not spin at fill speed. This can happen when the hubs do not disengage.
Crawl under the truck and try to spin the front driveshaft. If it freely spins then you are okay. If it wont spin freely your hubs did not unlock (some side to side play is expected, even if locked). Once you have done this, cycle the hubs from LOCK to AUTO (Unlocked) and try it again. Often times this will do it. If its still locked, cycle one more time, and back the truck up 10 feet. Again this almost always fixes it (temporarily).
I like to turn my wheels all the way to one side, doesn't matter which side, and reach in on each side and grab the axle U-joint and see if it will turn by hand. This tells you that the locking hub on THAT side is unlocked. Every owner of an ESOF truck should learn to do that, because sooner or later you are going to have hub problems.
Remember that one hub can fail and be locked, and the front driveshaft will still turn by hand, because the diff is an open unit. This is why you want to check each side individually.
Ok I tested it, my front drivrshaft will not spin in 2wd.. I checked the hubs they are in auto.. I didn't have time to turn the wheels and play with ujoints, but as I was lazing I asked my wife to look and it was turning the same speed as the rear one.. I tested the system in 2wd and gassed it in lose dirt and just the back wheels spun, I put in it 4wd and gased it and I couldn't ged the wheels to spin, I could feel the traction from the front wheels working, took out back to 2wd and the **** easily spun..
What's the deal? I will mess with the ujoint tomorrow, as I am also installing my new fog lights