Help On auto Hubs

[Vitucc]

Hello members,

I have read all the posts on the lovely auto hubs. Before i jump and make the purchase of the maual hubs i have a question to ask. When i cycle the turn on the the 4x4 from in the cab and the hubs are on they should lock right ? I can see the axles turn but no 4x4 action until I manually lock the hubs. My question is do I have a vacuum issue ? If i take the line off the hub am i supposed to feel vacuum with the 4x4 engaged in the truck ? Basically my question is do these appy with vacuum or not. These hubs are a pain in the ***. I would like to try and fix before I replace.

Thanks for any input provided.

[dhanna6powerstroke]

Originally Posted by Vitucc

Hello members,

I have read all the posts on the lovely auto hubs. Before i jump and make the purchase of the maual hubs i have a question to ask. When i cycle the turn on the the 4x4 from in the cab and the hubs are on they should lock right ? I can see the axles turn but no 4x4 action until I manually lock the hubs. My question is do I have a vacuum issue ? If i take the line off the hub am i supposed to feel vacuum with the 4x4 engaged in the truck ? Basically my question is do these appy with vacuum or not. These hubs are a pain in the ***. I would like to try and fix before I replace.

Thanks for any input provided.

They do lock with vacuum. Usually when guys have a vacuum problem with the hubs it also causes your heat to only blow out of the defrost vent. Does yours do that?

[Vitucc]

No . I have no heat issues. I just find it odd that the axles turn but no 4x4 unless i manually lock them.

[dhanna6powerstroke]

Originally Posted by Vitucc

No . I have no heat issues. I just find it odd that the axles turn but no 4x4 unless i manually lock them.

I'm assuming that you have the switch on the dash that you turn to engage the 4x4? Can you hear the vacuum pump running when you turn the key on? It is on the passenger side fender behind the battery.

[Vitucc]

I can hear something when I cycle it fron 2hi to 4hi on the pass side of the truck. And yes I do have the switch on the dash.

[Fireman40]

when you switch in to 4x4 your transfer case is also shifting into 4x4. so thats why your seeing your drive shaft spin. Most likely if your hubs are not locking you have a vaccum leak at the hub seal. there is a seal that goes around your locking hub and there is also a seal that goes around you wheel hub were it slided into the steering knuckle.

[7.3550Duty]

It sounds like the same problem i had with mine. I had a bad vacuum line that was split right at the fitting by the spindle. Just replaced the line with a little bit heavier duty fuel line and no longer have a problem. And my hubs are on auto all the time.

[Highbeam]

If your truck is equipped with the ESOF system, most are, then your hubs have two settings. Lock or auto. In any case, when you switch your dash switch to 4x4 there is a vacuum signal sent to the hubs. It isn't a constant suck but a pulse pattern. There is another pulse pattern to unlock the hubs. The whole auto hub setting is extremely problematic and not dependable so Ford was nice enough to give us a "lock" setting on the hubs. Use this lock setting if you need 4x4 and use the "auto" setting when you want 2wd.

Be warned. The crappy OEM hubs are also famous for not unlocking so even though your dash switch is in 2wd and the hub is in "auto" your hubs may still be locked.

Right now, you can buy Mile marker stainless steel supreme hubs for 89.50 from Summit racing. Mine were shipped this morning.

I have capped off the stupid vacuum hose system long ago and still have troubles with the hubs being very hard to turn and also not releasing.

[Vitucc]

Yes my hubs once I put them to auto they do not unlock the shafts i can still see them spin.

I pulled the vacuum line off of the hub with the truck running and felt nothing coming out of the vacuum line. The vacuum line at the hub looked good. How many are there i only found one on the passenger side but not one on the drivers side ? Where do i begin to trace for this possible vacuum problem.

Thanks to all for all the help.

[dhanna6powerstroke]

Originally Posted by Vitucc

Yes my hubs once I put them to auto they do not unlock the shafts i can still see them spin.

I pulled the vacuum line off of the hub with the truck running and felt nothing coming out of the vacuum line. The vacuum line at the hub looked good. How many are there i only found one on the passenger side but not one on the drivers side ? Where do i begin to trace for this possible vacuum problem.

Thanks to all for all the help.

There should be a vacuum line on the drivers side hub also. If the line is not attached, neither side will lock.