4X4 does not work! Yes I searched

[stroked1]

Well first off I did search here and Google and all that
My problem is that even when I manually lock my hubs it wont engage.
I have read that the TC motor may be shot.
Is that what you guys would try first?

About $140 at parts store

 

[Zmann]

so you get no verification of TC engagement through the dash lights ?

the system doesn't know if the hubs actuate so that is just checking the position of the TC motor

 

[stroked1]

Yes 4x4 and 4x4 low light does come on

 

[stroked1]

Will the light's come on even though the TC is not engaged?
Maybe its stuck?
I bought the truck with 100K miles and did try the 4x4 at the dealer, worked fine.
i tried using it 2 weeks ago and just this morning and not working
Truck now has 146,000 miles on it

 

[stroked1]

OK
Went out and checked the hub position.
Yes one was locked in and the other was not, so the TC motor is fine i do have 4x4 when hubs are locked in
Now to check the o rings on the hubs for the auto locking.

That is still not working, the vac pump in my opinion stays on too long so i may have a o ring failure.
Where can i find those o rings?

 

[Zmann]

Well We saved you from buying a TC motor so far

the hubs it can Be lots of seals/lines or a solenoid

I have to run but will post later

 

[stroked1]

Got home and took the hubs out and everything looked good. Added a bit of grease because im sure they have never been off. Put them back on and nothing.
So traced all the vacuum lines and didnt get any vacuum at the hubs. Got into the engine bay and found a "module"??? i guess its what it is. Vacuum would stop at that point. So i took off the truck and took the small cap off the top and found what looked like a round piece of real thin rubber. Didnt exaclty see where it came from but i put it back on where i thought it went. Looked to me like a check valve type deal.
All i did was put everything back together and tapped it a bit with a small hammer.

WORKS PERFECT NOW!!!!!!!!!!!
Goes into 4x4 immediately.

 

[HD F250]

I love it when the small hammer fixes it because it saves me from breaking $hit with the big hammer....LOL

Glad u got it working.

 

[Zmann]

well lets say you got lucky

because your checking for vacuum at the hubs was probably not done properly

the vacuum signal from the time you select 4x4 is measured in seconds
and then it vent's to 0

so you almost need someone to switch for you or be quick

I also took my solenoid apart and when the parts hit the floor I ordered a new one LOL

that was indeed My issue until later when I blew the main vac seal in the hub ,, that one is a little bit of a biotch

 

[ditch_dawg]

All of this is good to know. I need to do a little investigating to figure out what is going on with mine.

 

[Zmann]

if you have the dash light verification that you have 4x4

then g to the knuckle on each side and see if you can turn the shaft at the ujoint for each side

if one does spin that is your culprit side if both spin then you may have a solenoid issue or vac line

it's really easy to trace if you have a mighty vac type tester