I am a little confused on the proper operation of the auto front hubs. I have the hubs set to auto and when switch is on 2WD the universal joints close to the front wheels spin with the wheel. I was wondering if this is correct or should they disengage?......thanks in advance for info

 

They should disengage. They might after a while because every time you shut down they get a shot of vacuum but they probably need to be taken apart, cleaned, and lightly greased.

 

Here's a great write up on maintenance for the hubs

Welcome to guzzle's 4x4 Autolock Hub Lubrication Maintenance Web Page

All the stuff he has written up from a maintenance standpoint is here:

Welcome to guzzle's Ford PSD Maintenance Web Page

 

There might be some parasitic drag causing your axle shafts to spin but they should not have a one for one turn with your wheels.

 

Take a big screwdriver, stick it into the ujoint, and turn to eliminate possibility of parasitic drag.

 

2002 X,

I recently purchased my 2003 EX and found that the front axles were defintely turning even though it was in 2HI and the hub was unlocked.

I knew this was not right and informed the super duty tech of this.

When I had the ball joints replaced, the tech cleaned, lubed and replaced the axle seals and o-rings.

He also told me that not only is vacuum utilized to lock the hub, but also to unlock the hub. Anything not sealed, lubed or working correctly can make the locks stick in a locked position after having it in 4HI.

After he completed all the repairs, the axles are free and now the vacuum works properly to lock and unlock.

Good luck in your quest for free axles.

I'm sure when free, gas mileage will be a little better, and there will not be excessive wear on those front end parts.

 

on the passenger fender wall behind battery is a solenoid that controls vacuum to the hubs. pull the hose off to the wheels and suck it like a straw. you'll know if you have leaks then. mine had a leak on the y splitter down on the cross member where it seperates to both wheels. it would lock but wouldnt unlock. had to pull the hub and unlock it by hand. after fixing the leak it works fine
It very well could also be the solenoid is bad. I hear its a very common problem with the solenoids. Works like this... when the dash switch is moved the solenoid should apply vacuum for about 45-60 seconds to lock hubs and to unlock it does the same again just with less vacuum. there are more detailed innstructions in this forum on exactly how this systems works. I was in your shoes not long ago.

 

Good advice! I used the screwdriver and played with the auto/lock switch and it unlocked. I could now move the u joint while parked on the ground.

 

That means it might spin a little when you are driving but not engaged.