so my dad called me with an odd question today. when he engages the 4x4 from inside the cab and his front wheels don't pull at all until he gets out and locks the hubs? is this normal? how should this truck perform? i am new to the whole locking hubs thing so i am not sure what difference it should make and what the truck should do with just 4x4 on when locking hubs are involved? should it be like a normal 4x4 or what?
thanks in advance!

 

It's just like a normal 4x4, but the **** inside the cab replaces the floor shifter. You still have to have the hubs locked in or they won't turn. If you lock the hubs in and have the **** set to 4x2, then it will be in 2wd. The only way 4wd is going to be functional is with the hubs locked in and the **** set to 4x4. You kind of have a 2wd low range if you have the **** set to low range but the hubs not locked in. It's not good to run for any length of time with the truck in 4 and the hubs not locked in. It is, however, ok to run for short to medium distances with the hubs locked in and the **** set to 4x2, that way the truck is in 2wd but you don't have to get out and lock the hubs in when you need 4x4. Hope this helps, and congrats on your dad having an AWESOME truck!

 

The F350 uses vacuum to engage the front wheels when the hubs are in auto. If there is a vacuum leak the hubs won't pull in. On the right front fender inside the engine compartment you will find a vacuum pump, tank, and a solinoid valve for the front wheel engaging. Make sure the solinoid is operating then check for vacuum leaks. The vacuum pump also supplys vacuum for the heating and ac dampers in the cab. If they fail to the defroster when the 4x4 is engaged you have a large vacuum leak.