I know this topic has been beaten to death, but I have a relatively new-to-me '02 F250 4x4 with the auto/manual front hubs and the ESOF. From reading these forums I know that these hubs are known for losing their "auto" functionality. So, last night I shifted the dash **** to 4-Hi on an icy road and started a 3-point turn with the hubs in the auto position. I probably drove about 35 feet after turning the ****, but in the reverse portion of the turn only my left rear wheel was spinning on the ice. I rocked back and forth from drive to reverse seeing if that would engage the front wheels, but nothing. Got out, locked the hubs and was on my way with good traction. Should I just assume that my hubs have lost their auto function like many others?

 

Yup Welcome to the "Hub Club". If you're like me what comes next is; attempt to re-build the stock hubs. Results are they sometimes work, sometimes don't. Next. cruise E-Bay for a replacement set of stock auto/manuals but find they go for about $150 each with shipping (new are $300 from the stealer). Finally, reserach aftermarket full manual hubs and find that MileMarker #449SS are the best built and strongest manual hub made for the Dana 60, and a three year old can turn the dial to lock them up, they're that easy. Checked the Warn Premium Hubs but found out they're built down to a price in order to finance Warn's huge advertising and sponsership budget. The Warn's aren't bad so much as they aren't as good as the MileMarkers. Save the stock hubs that don't work to put back on the truck when trading or selling and transfer the MileMarkers to the new SuperDuty.
Sounds like if only the left rear was spinning you could use an Auburn limited slip too.

 

Or just keep the stock hubs in there and get out and turn them like you would with warns etc.

 

yes the bad stock hubs may lock but they will stay locked even when you turn them back to auto.

you sometimes cleaning and regreasing will work but still after while they will fail.

go with new aftermarkets.

 

Are you sure they'll stay locked? That didn't seem to be the case with my truck. I would assume that if they weren't locking in auto and required me to lock them in manually then they won't somehow stay locked once I go back to the auto mode.

 

I think that's his point (and mine); sometimes they will and sometimes they won't. You don't find out until you need it and turn the switch only to find that you have to get out and "lock up"(they are stuck in unlock position). The other side of this is you're driving on dry pavement on a nice day and the front end makes some nasty noises every time to make sharp turns (parking lot for instance) because of driveline bind because they never unlocked after the last use of 4x4 (stuck in lock position).

 

My '01 F-150 had a manual shifter on the floor with no electronic switch and no hubs to lock in. I loved that system don't know how it worked but it always worked. I put a lot of miles on in the winter and dont like to have to run with the front axles and drive shaft locked in just incase I come upon a bad strech of road.
I like to be able to shift in and out when needed. The 150s system worked great in that sense.

When I ordered my new '06 SD I went with the shift on the fly, due to reasons mentioned above. I dont like the idea of electronic shifting it just seems that its just another thing that can fail when you really need it.

Has anyone had any problems with the SOTF system or is there anything I should look out for.

 

Your F150 had the "Center Axle Disconnect System" on it. Lots of rotating mass even when you're not in four wheel drive. It's also the same system used by GM & Dodge. What you're referring to as "SOTF" is known as Electronic Shift On the Fly or "ESOF" for short. They are no problems with the servo shifted transfer case. There are LOTS of problems with the vacuum shifted hubs which is why a lot of us have switched to manual hubs. A new auto hub for the Super Duty runs $300 per side and it will eventually have the same problems as the originals did. As a comparison my MileMarker manual hubs ran $158 shipped and will outlast the truck. The MileMarkers are a "Mil-Spec" level of quality that Ford should offer as an option on the new trucks to improve their "cred".

 

How exactly does the ESOF work, what is still left turning when not in four wheel drive ? Does it just engage/disengage in the transfer case ?
Its good to hear that there hasn't been any chronic problems with the system.

 

An electrical signal is sent to the transfer case to a motor that puts it in 4wd hi and low. A signal is sent to a vacuum valve that sends a vacuum to the hubs to lock and release them.

 

Ive read that the vacuum lines going down to the spindle(hubs) can crack and not seal very well causing the hubs not to lock also.

 

I've read the same thing about the vacuum lines on this site several times. Wouldn't that be a better place to look first rather than just swapping out my hubs?

 

Depends on how long you plan on keeping the truck. The stock hubs are junk; sooner or later they're going to fail. Some people disassemble them and lube everything. Sometimes it works, sometimes it doesn't (mine didn't). Eventually, though, you will be left with a truck that is either always in 2wd or always in 4wd. If you plan on getting rid of the truck in the fairly near future, then I'd nurse the stock hubs. If you see the truck being in your driveway for more than a year, do yourself a favor and get aftermarket hubs. I've got MileMarkers, but I've also heard good things about the Warns.

 

Yes if you like. Remember that not only the hubs are the problem, but so can the vacuum actuator that is located behind the battery on the passenger side. Many a time, it is the vacuum actuator that causes the problem. If it does not provide enough suction, then it could lead to premature failure of the hubs. In a sense, it strips the hub. However, more often than not, it is a dirty inner hub that causes the failure.

A two person operation: Check the vacuum actuator. It should provide suction power for 20 seconds going into 4wd. It should then provide about 5-10 seconds for going from 4wd into 2wd. Check the suction at both the actuator itself and the spindle/hub. If all is well, then go for the hub removal.

Hope this helps...


biz

 

My hubs failed to lock and I traced to problem to a bad yoke seal. I could not pull a vacuume as per the service manual and mine ended up being a bad yoke seal. The yoke seal is behind the bearing hub and seals the drive shaft to the wheel spindle (yoke). The new seal is a pain to drive on but after 2 hrs and 34 bucks and it worked again. Best part---I still have auto hubs.