Hi all, I am new to the board, any assistance is greatly appreciated. I have a 97 expedition 5.4, 4x4. Last week I almost got stuck in some mild mud towing my boat. It appears the 4X4 is not working. When I engage the switch the indicater light comes on and the tranny appears to "gear down". The problem is in either 4H or 4L one tire just spins as if it was still in 2wd and as if the front hubs / axils are not locking or engaging. I have had bad experiences with dealerships and like to fix things myself. Does anyone know, is this system completely electrical or is it vacule driven. Any suggestion on where to start looking? I checked all the fuses and switched a mudule out that did not help. Could the anti lock brakes have a play in the 4X4 performance? Any assistance on this problem or assistance in where to get more information is greatly aprreciated.

Thanks

 

I guess 4WD is kind of like insurance. You should to have it before you really need it. When are you putting the truck into 4WD? With the autolockers the truck needs drive torque in a direction of travel for about 2 revolutions of the tires before they will lock in place. Since most of us drive forward most of the time this means one needs to put the truck in 4WD before it is really needed. It sounds like in your example you were stuck, put the truck in 4WD and since the hubs weren't locked you essentially stayed in 2WD. Replacing the autolockers with a good quality manual locker is an option. Of course that means you will have to get out of the truck and switch the hubs into and out of 4WD, but the drive will be there. Warn makes good manual lockers and with a little skill it ia a DIY project. The other thing to remember is that the front autolocker hubs can be severly damaged if there is much varience in the circumference of the front and rear wheels. Tires should be rotated as recommended to keep them close enough to not damage the hubs. One other thing, when you do get into 4WD, power will only be directed to one of the front wheels. Just like the rears without a limited slip differential.

 

Mike, thanks for the reply. After unhooking the boat and getting out of the mud I did try it in as many ways as possible and have tried it several times over the last few days with the same results. I do quite a bit of off roading with my 4 runner and the Expedition and this thing has always been a beast and goes through just about everything. Now it just spins one rear wheel like it did not engage. There seems to be some talent on this board and I am hoping I can get some technical advise on what to check. I figure I will get a repair manual and see what that has to say. Any idea what series of events takes place when the 4X4 is engaged? Is it all electrical or is there a vacume engagement to the front hubs?

Steve

 

There are no hubs at all, manual or automatic, on the Expedition. Everything on the 4X4 system is electric. This is totally diffrent from alot of the other 4X4's on the market. If you pull off your lug nut cover on the front wheel you'll see what I mean. I have a 97 also and wanted to know about the hubs also, then to my surprise, I found out that there were none. The 4X4 system runs on a solenoid in the back of the transfer case, ( Yes I know what you're thinking,"does it even have a transfer case?") There is a bunch of wires running into the back of the Transfer case into the solenoid, these tend to hang up if they get dirty. If you have done any serious 4wheeling this might be your problem. A friend of mine with a 98 had the same problem. He found out from a ford Technician what it was. He then took it apart and cleaned the solenoid and put it back together. He hasn't had any more trouble to date. Now if I can just figure out what is wrong with my A4WD we'll both be set! I hope this helped you out a bit.

 

Mr 4X4 Freek, thanks for the response, that sounds like a logical place to start, have fun in the mud.