4 Wheel Drive/SUVs: 4 wheel low will not disengage, linkage problem, auto parts stores

Question
I have a 1998 expedition.  I can't get the 4 wheel low to disengage

Answer
Pat,

To give you a simple answer would be extremely hard without looking at the truck.  This problem is usually a transfer case problem, and could be as simple as a linkage problem.  Some of vehicles use a vacuum, or electrical switch/solenoid on the transfer case, which has vacuum, or electrical lines running to the front differential that can be pulled loose, or the switch itself can be faulty.  If your transfer case is shifted electrically, then it may be just a bad ground to the transfer case.  These problems can be traced out fairly easily.

I would suggest that you purchase a repair manual, and try to trace out the front wheel drive section, starting with the front hubs.  A Chilton's or a Hayne's manual can be purchased at most auto parts stores for $20, and they have a lot of information on basic trouble shooting, and repairs. These manuals are designed for a year or range of years for specific vehicles, and are invaluable if you are planning on doing any repairs yourself.

Another thing to try, would be to have the transmission, transfer case, and differentials serviced.  This is simply changing out all of the fluids.
There is a slight chance that there are some dry components that are causing some drag on the shifting mechanism.

Carl