I was reading this thread and came across the above. Maybe I'm not understanding something here or maybe something changed after 1999, but are you shifting in to 4x4 LOW without the transmission being in neutral (or clutch pushed-in if manual transmission).

Bold text below is copied directly from my 1999 owners manual.
"Shifting between 4x4 HIGH (4WD high) and 4x4 LOW (4WD low)

1. Bring the vehicle to a complete stop.
2. Depress the brake.
3. Place the gearshift in N (Neutral) (automatic transmission) or depress the clutch (manual transmission)."

Also if the truck is moving.

"If equipped with the Electronic Shift 4WD System, and the
instrument panel control is moved to 4WD Low while the vehicle
is moving, the system will not engage and no damage will occur to
the 4WD system."

Again, maybe I am just confused.

 

Ok guys I found the issue and it seems to be resolved. Thanks for all of your help! I took the hub out and the gears and spring fell out. Turns out the snap ring that holds everything together had slipped off somehow. I found a photo someone else on the forum had taken a while back. The hub on the right looked like mine.


I put it back together and the it locks up properly. The drive shaft will no longer turn if both hubs are locked. 4x4 high and low are definitely working as well too. My only remaining concern is how on earth this happened and how I can keep it from happening again. The only thing I can think of is it was not reassembled correctly when the shop serviced it in the spring??

Any ideas?

 

sounds like it to me.
mine have been in the 02 for 6 years now, and the 88 has had them on it for 22 years. i have never had them off or apart on either truck.

 

Glad you got it figured out -- that was the exact same issue I had.

MM

 

Thanks me too. Did it ever happen again, or was it a one time deal?

 

Had the exact same issue on my 99 powerstroke 250SD. Stuck in a ditch, in 2 ft of snow, 8000+ feet up on a mountain pass, and only 4x2 as the hub failed!

It currently has ford autolocking hubs (although the truck doesn't have autolock switch option fitted). I intend to replace both hubs with Warns or other aftermarket hubs.

Can anyone venture an opinion as to whether any of the other cheaper hubs are worth consideration, and whether the warns are a direct replacement for the autolock ford hubs, will they simply bolt straight in with the same locking ring and the ford units

 

I've heard their a direct bolt in.

Glad you got er going jlstorm,

 

Well not sure everything is fixed. On the way home from hiking today I noticed a whining sound coming when I was driving and it seemed worse when I turned. When I got the truck home I put it in park still running. The whine was still there. I crawled underneath and shot this video with my phone

It looks like there is quite a bit of red fluid dripping on the front axle housing and what I assume is the steering stabalizer.. The tranny from what I can tell is dry. I suppose it could be power steering, but why would that make noise when nothing was moving? I'd imagine I didnt break something else when I fixed the hub, but the coincidental timing is a bit odd.

Click to play (it might take a second or two for the video to show up).

 

Most likely the high Pressure power steering line blew. They like to come apart at the fitting.

Unrelated to the 4x4, but you have the same luck I do.

 

Sounds like power steering to me aswell, the sound you here is probably the PS pump running with no oil in it.

You have the same luck I do

 

Thanks for the additional info. I guess I'll get underneath tomorrow and see if I can figure out where the power steering fitting is and if that is the issue.

Assuming it is the power steering. Do I need to put a specific type of power steering fluid in, or can I just pick up anything from the auto parts store?

 

I know the diesels call for ATF. Not sure on the 5.4, but it is the same pump and box so I don't see why it would be different.

 

From pg 239 of the owner's manual

 

Thanks again guys! Sorry, I didnt even think to check the manual. I'll keep yall posted.

 

Just thought you might like a reference instead of an opinion on what to put in there!

Happy New Year - may your truck run flawlessly, and your fuel be cheap!