Hi everybody!
just got stuck in the sand, front diff. doesn't engage. How does it work anyway (I am not really a mechanic ). does it engage trough vacuum? if yes, where does the hose go? here is my deal:
there is a hose coming from the front differential but it ends open right by where the brake-fluid-distributer sits (near the front drive shaft, kinda' in the frame) now I would assume that this hose should go somewhere and get vacuum (from the transfer-case or from some actuator?) - but I can't find neither the other end nor where it should go!
could the rest of the hose have been ripped out somehow or am I totally on the wrong track?
looked at vac diagrams but they don't tell about the 4x4 engaging system...
any ideas?

 

I know even less but that hose sounds like the vent hose and doesn't hook to anything. Do you have push button 4x4 or manual shift. If manual shift the hubs are not locking in, get a set of manual hubs.

 

hey thanks for the lightning reply
I have automatic tranni/push button 4x4, the button lights come on, tested on the front drive shaft- I can spin it without 4x4, it's locked when 4x4 is engaged, so I suppose the transfer case is doing its job (also hear the little bang when engaging).
now if my dead-end hose is a vent hose like you say - how does the front end engage? I know it does 'cause usually I can hear it disengage whenever I go from 4x4 to 2wd.
I used to have a Blazer (I know - I should'nt say that here ) and that front end engaged through a vacuum driven actuator (sitting somewhere underneith the battery) which pulled a wire rope going inside the front end to lock it.
Well I'm just learning the Ford-way so I'm gonna crawl under there again....


-----------------------------------
'93 F150 V8 5.0 4x4 automatic

 

ok forget what I said, follow hose to diff, is it hooked to a actuator, if yes then look on the left fender for the other end of hose. If you can hear the vacuum solinoid work then find it and hook that hose to it.

 

ok, that hose is the only thing coming from the front diff,
now the question is - is my differential switched or is it permanently locked and that hose is indeed just a vent hose or does it unlock - got unsure of that cause I got it out of the sand, disengage the 4x4 button, reverse for a couple feet and still hear it clicking in the front diff!
if it is permanently locked I shouldn't be able to spin the front shaft at any time right!? so in that case the front diff is broken.
And I am not able to find any actuator or hear any hissing sound.

 

No, no, no, no, no...... We're talking about a 93 here, not a 97-up.
The hose is just a vent hose and nothing more.

The first question is whether he has the automatic locking hubs or the manual locking hubs. If they're automatic locking hubs, they're shot. Replace them with a set of Warn manual hubs. If he already has manual locking hubs, he needs to get uot and lock them, then the 4wd will work.

We know it's not a transfer case issue because he already said it locks the front driveshaft when in 4wd. That eliminates all transfer case and shift motor issues. The only other thing to engage or disengage is the hubs. That generation of automatic locking hubs is a weak design prone to failure at the least convenient moment.

-Joe

 

thanks joe - now what are the locking hubs - manual or automatic (again I'm not much of a mechanic plus english isn't my mother-tongue ) - do you mean if I lock the wheels manually from outside ? I don't, there is nothing to turn or switch.
anybody willing to give me a lesson about automatic locking hubs and how they work?
thanks a lot guys - its great to get instant help here!!!

oh - so here is something else that might be part of the whole story:
over the last about 100miles I heard a weird noise from the front starting at about 20-25mph - thought I know that noise from former experience that told me its bad wheel bearings - didn't go faster than 40mph eversince, got a set of wheel bearings and was about to take the truck to the mechanic to change them...

 

If you don't have anything to turn by by hand at the center of the front hubs, you have auto hubs. See GIJoeCam's response for what you need to do.

 

so i was right then i was wrong hmmmmm

 

hehe yeah sorry I might have confused you there...
so the differential itself doesn't have anything to do with the 4wd engaging? the problem is right by the wheels as I understand?

 

Correct, although I don't remember how the front axles on pre-97 engage, whether by motion or by vacuum.

 

warn hubs is the way to go, pretty easy to install, but you need a special tool

http://www.warn.com/

 

...and my wheel bearings might still be alright, the noise might come from the wrecked hubs... well I'll stay out of the sand and check with a mechanic asap its hard to find a good one down here (Belize - www.windschief.com)