When i engage the 4x4 from the dash dial switch, the "4x4" or "LOW RANGE" light illuminates on the dash as if it's activated when the dial in is it's respective position. After shifting to low range, the truck has the traditional lurch when put into gear. However, the front wheels do not receive power in either mode if the hubs are in the Auto Locking position. After rolling forward, no engagement. Reversing for a few feet...no engagement. In 4-hi, it acts as if it's still in 2wd. In 4-lo, transmission acts like 4-lo. But in either case the front wheels receive no power and steering is just as sharp as when in 2wd. When i manually lock the hubs, front wheels receive the power and steering is like it should be (not sharp turning). What's wrong? Do the hubs need replacing? I'm not too familiar with the Ford systems or the workings of the solid front axle. I used to have a couple of Z-71's and although they only have auto hubs, i had this similar issue before with them and had to replace and electrical part or actuator on top of the front axle. Does the SD have this and could this be the problem? If it's not the hubs themselves, i would think it's an electrical thing since the hubs engage when done manually. But that leads me away from it being a hub issue. IDK. Any help is greatly appreciated.

2004 F250 4x4 CC Lariat 6.0

 

The short answer is this system has caused a lot of people a lot of problems. Lock the hubs in manually and you'll be fine. Most replace the auto hubs with a dedicated set of manual hubs anyway.

The longer answer....

The hubs are vacuum actuated. A vacuum leak can cause the hubs to not engage. This can be made very obvious by checking the HVAC vents in the cab. When I had a vacuum issue, my HVAC went to the defrost position and no matter what I did I could not change the vents. The initial suspect is the rubber vacuum hoses that go from in the wheel well down to the axle knuckles. After years of weathering, they crack. No vacuum means no HVAC when 4x4 is engaged and no auto locking hubs.

The next suspect is the small vacuum solenoid valve mount at the passenger side front of the engine bay.





Mine cracked so I had a vacuum leak all the time. My truck has manual hubs on it, so I was not concerned about capping the supply line to the solenoid.





Finally, there are some seals in the knuckle and hub that can be replaced if it is neither of the above items. This article covers the complete disassembly for replacing ball joints. I believe the yellow seal is one of the vacuum culprits. Also, the o-ring on the hub itself is another.

2004 F250 Ball Joint Replacement

Here are 2 articles that explain how to remove and disassemble the hubs to clean and service them.

2004 F250 ESOF Hub Service
https://www.ford-trucks.com/forums/1...l#post14810028

I hope this helps

 

Nice write up with pics. Reps coming your way.
I know when we too experienced that issue with my brothers 99 F 250, the wheel well vacuum lines turned to dust when pulled on.
Changed them out and all worked well.

 

Thanks! I can't take the credit though, 1975stroppebaja (Jason) is the one with the frontiernet site and writeups. He deserves way more credit than me... I just figured out how to remove the **** from the hub on accident

 

HVAC works fine. Defrost, upper/lower vents all work like they're supposed to when 4x4 is changed on dash. I'll inspect the lines anyway. Is it possible that the vents will work fine even if there is a leak or broken line that runs to the knuckles? If it's the solenoid that you show, is there a specific one to get at the parts store or is it a general type? I'm a DIYer and have a respectable selection of tools I've acquired over the years and am not afraid of busted knuckles, but I don't know if tearing apart and rebuilding some hubs is something I should be getting into. I've never done that before or gotten that in-depth with a front axle. Is it advised that I find a shop to do it instead? If I decide to switch to a set of dedicated manual hubs, is this something that I can easily do myself or should I get a shop to do it? Recommendations on hubs?

 

I have a 2006 F350 5.4l Lariat CC - replaced my auto hubs this summer with Warn manual hubs. It was a piece of cake changing them out, and I am not mechanically inclined. The day before I did it, I sprayed WD-40 all over the hub. Unscrew the hec bolts, and the whole hub sludes out easily in one piece. New Warn hub goes in simple in a few pieces.

I've since plowed a few times snd they work perfect.

 

I had that trouble with my 2000 F-350. The seals inside the hubs where shot. I asked the stealership if they stocked replacements. They said yes they did as they go bad all the time.
There is a special tool to pound the new seals in without damaging them.


My question still to Ford is "If these seals are so poorly designed, why haven't you fixed the problem?????"

 

I have a 02 F250 5.4 and the 4x4 stopped working today while at the snow, luckily I had chains as a back up. All the 4x4 lights turn on, I can hear the transfer case engage, and I can hear it whining while driving but the front wheels have not power to them. I put the hubs to the manual position and still don't get power to the front wheels. I have to have the 4x4 working in another two weeks when I come back to the snow. This is a daily driver and only use the 4x4 Lin once a year. I do put it in 4x4 once a month and drive in a straight line just to get everything moving and make sure it's working. Any suggestions?