1997 5.4L Expedition

Driving to work in slush, turned 4WD selector switch to AWD. Slush got worse, turned switch to 4HI at about 20 mph. The dash indicator toggles back and forth between AWD and 4HI, but I think nothing of it as it has done that many times before. Suddenly I hear a loud clunk. I actually thought I ran into something, the noise was so loud! I realize that something wacky is going on with my 4wd and try to change with the selector switch although nothing changes. I am only about a block from work so I continue and park at work. I try reverse and it seems okay. I turn off the truck and go into work. When I leave from work, the 4WD seems stuck in some sort of limbo. No dash light indicates that I'm even using 4WD but it obvious that I'm in 4LO. I make it home at a surprisingly low rate of speed!

From reading these boards, I try the obvious, I put the truck in neutral with the brake on and switch the selector to all the selections. Amazingly I do get the dash lights to tell me I'm in 4LO, but I'm unable to get it to switch out.

I pulled some fuses that might be related and all look good. Then I remove the actual selector switch and clean it although it didn't look like any of the contacts were corroded. That didn't change a thing.

All I can tell now is when the key is turned on (from off, obviously), I hear six clicks then the dash lights tell me I'm in 4LO. Doesn't matter if I turn the key on from neutral or park.

This board has given many other possible solutions that I will explore including the GEM, vacuum leaks, relays, switches, etc. I'd just like to know if any of the symptoms I've described show an obvious way I should proceed? Maybe those six clicks mean a certain diagnosis...maybe? Hopefully?

Thanks for any help you can give! I appreciate it!
Daphne

 

It might be that since you've driven it in 4lo on a hard surface the drivelines are bound up to the point that the transfercase shift motor can't disengage the low range. I would try to jack up the rear end (actually both ends would be good if you have 4 jack stands) to relieve the tension (put the tranny in neutral but make sure you have the wheels blocked so it won't roll). Then try to spin the wheels by hand and see if the transfer case is engaged or not. Finally take it back down and try the shift selector again and see if that fixed anything.

 

Well, got it jacked up but couldn't disengage the wheels. However tapped on the shift motor and heard it buzz. I'm now out of 4LO. So I will replace that motor.

I'm still freaked that it just jumped into 4LO. If that shift motor was failing, is that why it jumped into 4LO? Or is there another component that is also failing?

Thanks,
Daphne

 

Okay, I lied. It isn't out of 4LO although the dash indicator stopped displaying that it was. My test drive proved that it was still in 4LO.

I may have to, gasp, take it to the Ford dealership!

 

Yeah, unfortunately that may be your best bet. It sounds like maybe you have something wrong with the electrical system that is making it shift in to LO when it shouldn't be.

 

In case anyone would like to know who this has ended...

It was the transfer case shift motor. Part # YL1Z-7G360-AB. Now I just need to have it snow here so that I can test it out!

Thanks for the words of wisdom! Hopefully there will be more words of wisdom when I make a post in the Explorer section to see if I can figure out what the heck is wrong with that motor vehicle!

Daphne