I have a 2002 Excursion with 7.3 diesel. I have had occasional problems getting it out of 4wd but it always came out eventually. The last time I used the 4wd it wouldn't come out so I took all four wheels of the ground and ran a power wire to the motor that engages and disengages the transfer case.
I can power up the transfer case the same way the axles turn but hubs won't engage. It is a shift on the fly. The switch seems to be good, I checked it with ohms meter. I have been told there is a way to manually engage the hubs but I have no idea how and can't find a manual on the the 4wd in this truck any help would be greatly appreciated.

 

The shift on the fly will only engage when you are going over 15 MPH and the switch is in 4X4 position.
There should be a raised external slot on the outer part of each wheel hub which you can turn a half turn clockwise and that will manually engage (lock) the hub. Same for the other side. To disengage the hub just turn each center slot counterclockwise (to Auto for automatic). Once the hubs are locked , turn the inside switch to 4X4 and you're ready to go.

 

Thank you for the reply By raised slot are you talking about the black thing on the outer axle that looks like it should turn but wont. I'm afraid to force it the truck is 9 years old and that has never been turned could it be the right thing and just frozen?

 

The four wheel drive use to engage immediately when switch was turned on didn't need to be going 15 mph or I would have never got my boat out of the water

 

Now could the switch it self have gone bad? Is there any indication that the 4x4 is trying to do anything at all or is it does nothing happen at all once you turn it on/off? certified volkswagen of portland oregon

 

The transaxle engages, the axles turn, the wheels don't.: I have been told there is a way to engage them manually I just haven't been able to figure how to do it.
If anyone knows how to do this I would love to hear how it is done.
Thank you
Jack

 

Did you check your owner's manual? It explains how the shift on the fly works.

 

Jack, I haven't heard anything from you . Did you figure out that you had to turn those flat tabs on the center of the front wheels in order to lock the hubs manually.
Were you able to check the owner's manual?

 

I have tried to turn those black tabs on the front of the wheel. They just won't turn.
I put a strap wrench on them and tried several times, even got a body builder friend who is strong as an ox he couldn't turn them. The axles turn the wheels do not. do those black caps come off. I haven't found my owners manual and have tried to buy a book on four wheel drive haven't been able to find one. I have to go to upstate New York next week and sure hate to go without 4 wheel drive. Is there a manual hub I can replace these things with?

 

Jack try this website for the owner's manual for your vehicle.
fordfleet.com
You don't turn anything except the flat protrusion that sticks out from the center of the hub. Let's hope the website offered will assist you.