My 08 F-150 FX4 with ESOF has a question. As I understand it, the hubs lock/unlock at the wheels. I go park the truck in the driveway, the switch is in 2wd. Why is it that the front drive shaft doesn't turn? In theory, with the hubs unlocked and the transfer case in 2wd, I should be able to climb under the truck and spin the front driveshaft freely, even in park, right?

 

The Integrated Wheel Ends engage when there is no vacuum so if the engine is off the IWEs are engaged and you will not be able to turn the driveshaft. Vacuum is required to disengage the IWEs.

 

OK, thanks!

Tried it again with the engine running and it worked as stated above!