I have a 2008 Ford F250 with 6.4. Having alot of problems with the 4X4. Went to put the truck in 4 wheel drive one day and noticed the light on the dash never came on to engage 4X4. Of course we had a big snow storm coming and I didn't have 4 wheel drive. I drove the truck across town and decided to just try 4x4 again and it worked that time. I got the light on the dash and could hear the transfer case shift motor engage. Came out a little later and tried it and it wasn't working again. Took truck to shop where they replaced transfer case shift motor with a remaned motor from oriellys. 4x4 worked for a few weeks then just started doing the same thing again. We thought maybe that motor had problems also so had it replaced too. Truck is still doing the same stuff. Sometimes it works sometimes it doesn't. Figured out that if its not working and I leave it in 4x4 and unhook power to shift motor then plug it back in it will engage 4x4. Just wondering if anyone else has had this problem because I've bout had my feel of this truck. I've seen some post on here but sounds like everyone i've seen their motor just stops and doesn't work at all. Thanks

 

The obvious thing is either the transfer case motor wasn't the problem, or was only part of the problem. That will be 65$. Thanks .

Seriously, intermittent function points towards a vacuum or hub issue.
In my experience this can happen when 4X4 goes long periods without being engaged or gets gunk in the hubs.

The 4X4 cluster light throws a wrinkle into diagnosing. Aside from the dash light, how are you determining if you're in two or four wheel drive? Are the axle shafts free turning or locked at the front u-joints?

What did you try regarding your hubs? Assuming you have the auto-lock hubs, is the selector free turning? If so, when you move them from auto do you feel them engage or "click?

Sounds like you've searched here on ESOF. This will provide information, lots of information, on about everything that can go wrong and how to diagnose and repair.

From what you wrote, I would verify the hubs and vacuum first. Ford sells a kit with new seals and torx bolts pretty reasonable. A good cleaning is always good insurance against having to buy new hub$.

If all the usual suspects are innocent, then maybe you do have a bad computer control or transfer-case issue.

Good luck,

MOJoWales

 

I do know that the passenger side hub has a slow vacuum leak but didn't think that would hold out the transfer case motor from engaging and giving me the 4x4 light on the dash board. When its working I can hear the motor shifting under the truck. I've even left it in 4 wheel drive one night and got up next morning and didn't have the 4 hi light but truck was stuck in 4 wheel drive. Drove around awhile and light just came back on then I could put it back in 2 wheel drive. Could slow leak on vacuum cause transfer case motor to not engage? I figured since hubs can be manually locked in the motor should work no matter if there's a vacuum leak or not. I'm definitely not a mechanic and need all help I can get before I get rid of truck. Thanks.

 

The most common problem is hub or vacuum line failure.

Two things that muddy up the diagnosis:
A shop mechanic did the transfer-case motor swap so they must/might of had a reason.
The dash light 4X4 indicator.

First, have you checked for any codes with a scanner?
Barring this, and if it were me based on what you have stated, I'd start with checking the hubs for function and vacuum. It's really easy and there are some easy to follow step by step instructions here and online.
One thing to remember is to pick up one seal kit per side from Ford if you remove the hubs. The big O-rings fail over time and it's cheap and easy to do.
Checking the vacuum lines to the knuckle is easy too. Line is cheap and easy to replace.
Working backwards from the knuckles is pretty straight forward and I'm guessing that the shop would have done this before jumping to the motor replacement but if not, this needs to be done.

If these check out then it gets more involved, but these are the usual suspects.
Next would be the vacuum solenoids, vacuum pump, and lastly the computer controlling the ESOF and internal workings and linkages on the transfer-case.
I haven't pulled apart a newer Super Duty transfer-case so I can't offer anything there other than I've never had to.

Again, I'd start with hubs and vacuum.
The thing that throws me a bit is the 4X4 indicator light but I'd still start there.
You already know one side has an issue and the hubs can be temperamental.

Good luck,

MOJowales

 

Thanks. Think I'm going to replace the bad hub and go from there. The 4x4 indicator is what is throwing my mechanic off also. They replaced a seal but said it still had a small leak. Drivers side was good. Maybe computer sees vacuum low and doesn't allow motor to engage. Not really sure. Doesn't explain why it works sometimes and sometimes it doesn't. Thanks for help. Will post after get hubs replaced.

 

If your mechanic replaced the hub O-ring seal and it still leaks you probably have one of two things:
1) A bad knuckle seal. It's the big one you have to pull the knuckle apart to get to. Replacing the hub almost certainly won't effect this.
2) The hub diaphragm. If they didn't check this in the hub during the seal replacement then it might be leaking. It's a bladder type thing that sits under the actual selector switch. If that's gone, or if the plastic housing where the hub actually engages is FUBAR then you have to replace the hub.

Makes a bit more sense now with the 4X4 light throwing your mechanic for a loop too.
Have you specifically verified that there aren't any codes stored? Could be something that isn't giving a check engine light and would help sort it out.

Anything else "weird" happened?

In any case, I would look to remove and inspect the hubs, both sides, before throwing money into new ones from Ford. They are pricey. And I would be "hoping" that they are keeping the 4X4 light from working.

MOJoWales

 

Mechanic used a portable pump to check vacuum on both sides. Said drivers side held good vacuum but passenger was losing vacuum through the front of the manual auto lock out. Said he believed something was wrong with the hub itself. Hub on that side has been messed with before because the lockout is a different color from the drivers side.

 

Okay. With that, and it being your money , a new hub sounds more justified.

Without stirring the pot, I'm curious about why the transfer-case shift motor was replaced before having good hub function because your mechanic seems to have done a proper vacuum test.

Anyway, knowing more about what your mechanic has done you seem to be on the road to fixing the ESOF.

MOJoWales

 

Sounds to me like you have a bad hub. Also check the 4x4 switch, on the gas engine models it is right on top of the radiator super easy to get to and to replace. It might be in the same location in the Diesels. Also look under the hood in the relay box next to the master cylinder, check and make sure all the relays and fuses are pushed in all the way and while you're there check for blown relays.