I have a 97 Explorer that the 4WD hi/lo is flashing 6 times waits
about  2 minutes and flashes again 6 time.  I've noticed in tight turn
there is shutter in the front wheels as though the 4wd is kicked in
but it isn't in the selector.  As a matter of fact, the selector now
doesn't work.

I've heard of a speed sensor that might cause this.  Is this the spedo
sensor on the transmission or is there another?  

If so, is there anywhere on the web showing how to change this?

Any help would be appreciated.

Thanks,

Jeff