Hi Guys,

Just purchased a 2003 SD...and found out after that the ESOF does not work! I tested it in a parking lot and hear the transfer case engage...and thought the hubs engaged too...OOPS...NOT!

Later after getting it home and taking it for a nice "off-road" experience...almost got stuck in sand before I noticed the front tires were not pulling while in 4x4 Hi. Tried the 4x4 Lo too...with out success. I did have to get my butt out of the truck to "LOCK" the hubs. They did seem to pull then.

Any ideas what I should be looking for to help with the front hubs engage using the ESOF?

Is it possible to actually hear the vacuum pump next to the battery pulling vacuum?

Which vacuum hose should I pay more attention too? The single "red" or the "black" hoses?

Thanks for any ideas??? Also, I really want to keep the ESOF and not convert to manual. This is my first truck with ESOF...as my previous truck '76 F150 4x4 390FE was all manual.

Heck...still love this new/used truck! I will take some pictures soon and post in my gallery. All stock no modifications done to my knowledge anyway.

biz

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2003 F250 SD SC SWB 4x4 V10 Auto ESOF FX4 3.73LS
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No. You will need to test the vacuum solenoid to make sure its pulling vac. Someone will need to turn the dial while you check it. See below:
It's the smaller diameter line which is black and runs over the top of the vacuum cannister that's located behind the battery. This line is connected to a 90 degree ell. You can disconnect it there and test for vac.
Congrats on the new truck, biz I hope you get as much enjoyment out of it as I have mine.

Check back with us and let us know if the solenoid is working.

 

sounds like you think esof is something its not.... your 4x4 is probly working... its just spinning the front driveshaft and axles thou and not the wheels until you lock hubs... other auto makers have the hubs lock auto matically... not ford... i like it better. seems toughter... and always in favor of mechanical then electric for relability. what i do is, if i know i will need 4x4 when i head off road i just lock the hubs... you dont wanna go to fast or for to long if its not needed thou... cause it will be spinning the axle and front driveshaft and will wear out you bearings in the spindle and the slip joint on the driveshaft. TRUST ME but i have been using my superduty for many purposes for 2 years now... and gettin off your BUTT to unlock the hubs is not a big task,unless your allready stuck!!! so just get off your butt and be glad you bought something as tought as a ford. plus if your complaining of getting up of your ole' ****,then your probly could use the extra excercise

 

Well, congrats on the new truck, to bad you've already experience the esof problems. I'm not sure what krazykyle is talking about but I have had the same problem with my 03' which has been to the dealer 5+ times for the auto locking hubs, finally they replaced them under factory warrenty (which you may still have a few months left, you may want to check!!). The hubs tend to loose vacume due to corosion, salt, sand, and dirt getting into them. once they loose vacume the partys over for the shift on the fly which makes it real nice that ford realizes the hubs are junk so they give you the option to get out and manualy lock them in. If you have no warrenty just leave them alone and make sure to turn the hub lock a few times a month to make sure they don't freeze up and then just use them like a regualr lock out hub. the Factory hubs are pretty spendy and really aren't any good so if you want to replace them your better off spending $200 for a good set of warrens but you still won't have shift on the fly. Good luck hope this helps.

 

Krazykyle ,we usually don't talk to people around here like that untill we get to know them a little.And then we use a little caution at that.
That being said I think yours was alittle harsh.


For the orignal poster
As Mr big has said and SLE the vacum hubs are suspect.
The main cause of not working is dried out o-rings and dirt and grime within the hub.
There are 2 o-rings that fail one on the wheelbearing and one on the 4x hub itself.Using a little wd-40 spray on the hub or silicone will keep the hub o-ring from failing .The one that seals the wheelbearing hub usually fails because of heat generated fron braking and the wheel bearing itself.
They need to used to keep them soft and to prevent drying out.
They might just need a good cleaning inside the hub also.
Rich

 

ahh thats the diffrence i have warns on my truck.. never new they were auto locking stock "with maunal override" . oh excuse me "POSTMASTER" fortyfords.... dont tell me how to talk... thanks that sucks that you cant take some jokin... although i see you old guys jokin all the time. so far i dont think i have said anything bad... joking about BIZ4TWO bein "fat" an "lazy",cause he wont get outta his truck to lock his hubs... so what... probly 70-80% of the people on this site are overweight... whats happens when your old and sit in front of the computer all day so if thats why it affends you FORTY, well then deal with it or go to the gym. thanks, have a nice day.

 

Sorry, this is COMPLETELY incorrect, at least in regards to the Superduty.

The hubs SHOULD lock when you turn the **** on the dash. They may require some motion to get them to engage, but they are TOTALLY automatic. The "Lock" position on the ESOF hubs is for that (apparently often) time when the hubs do not lock by themselves.

I've gotten my SD buried to the front axle in a garbage pit in my backyard that I didn't know existed - well, it was about 50 years old, so I don't think the previous owners did either Put it in 4x4low with the **** on the dash and idled right out without manually locking the hubs. That was about 6 months after I bought it brand-new.

A year later, my front hubs started randomly locking or un-locking at the most inconvenient times. I learned alot about diagnosing the system.

Here's my input:

1) When you turn the **** on the dash to 4x4, the GEM sends a 20 second vacuum pulse to the front hubs. It's been my experience that if the hubs don't engage during this time, when the vacuum is released, the hubs will not lockup after that. So, you have 20 seconds after turning the **** to get the hubs engaged - which means rolling, and possibly turning the wheel if you have a stubborn hub.

2) When coming out of 4x4, the GEM sends a 5 second pulse to the hubs. If there is any load on the drivetrain at this time (like you're sitting still and the axles are at least somewhat bound up, or you're going straight on a level flat surface like wet pavement) they will not unlock.

3) I completely forget the colors of the lines, but Big Orn (Ron) is most likely correct Check for vacuum at the line that goes from the vacuum solenoid down to the front hubs. Turn on the ESOF ****, you should see 20 seconds of vacuum. Turn it off, you should see 5 seconds of vacuum. Check it with both a "T" and directly from the valve. That way we can see if there's a leak down-wind of the solenoid (well, up-wind in terms of vacuum )

4) Try locking the hubs manually, and see if you have 4x4.

Get back to us with answers to 3 and 4 and we'll go from there

art k.

ps: For my opinion on the ESOF hubs, you can view my gallery - notice the NON-STOCK hubs behind the stock beauty ring

 

None of what you just said needs to be in this thread.

The problem with another "get off your lazy butt" post is we've heard it THOUSANDS OF TIMES ALREADY.

People come here asking technical questions - they don't need to be told to get out and lock the hubs when something mechanical is not working as designed.

 

yea i know... and i offered the best advice i had that i have learned from my expierences... i was wrong about the hubs,i have warns, so i have had diffrent expierences then you guys withthe stock hubs... and i was just jokin around, and i havent heard that jokin was outlawed in these forums... i didnt mean it to be hurtful... to biz4two... an i dont wanna be told how to talk. an so far i have heard nothing from biz4two sooo hopefully he understood i was joking.... so if/until he does say something about it you guys should lay off... POSTMASTERS!!! do i salute you now????
origanally posted by krewat:
None of what you just said needs to be in this thread.

haha if not here then were.... ok POSTMASTERS, thats it! meet me in the parking lot behind the ole' school house... YER' DONE

 

Thanks guys for all the GREAT info (minus krazy... ). I will certainly look into the ESOF system closer this week.

My first test will be to actually switch it into 4x4 HI while on the move. When I tried this past weekend...I was always stopped.

If that does not work...then I will move to the vacuum solenoid test...and make sure I get the 20 second pulse...and 5 second off pulse.

I will then move to the vacuum lines if the solenoid works. I want to leave the hubs last on my list...if possible. Unfortunately no warranty here. My SD has over 88,000+ miles (I just put 640-670 miles driving home from buying it in Dallas,Tx). Good news...I averaged 14.7 mpg on the trip back to ABQ. Very happy with that mileage...

Looks like #4 is a "YES". Once I put the hubs in the "LOCK" position...I could see the driver side tire dig in...and did also see the passanger side tire dig in throwing dirt/sand past the window.

Wish I could work on the truck after my daily grind, but with the new time change...I get home in the dark. I suppose I will have to wait until this weekend. Will post back then...

Thanks!!!
biz

 

Biz4two, for a peice of mind and good maintenance practice remove your hubs and disassemble them. With the hub removed you will see a c-clip and a retainer ring. Remove both and tap or rap, which ever it takes, ontil the guts come out. I think things get dried out on the inside and need to be cleaned and lubed. You will see how simple these hubs and how they work. In the auto mode it's all vacuum. With the internals removed you will see the rubber diaphram and you can check it's condition. It seems to be a pretty good thick material. Also while the insides are removed spray some WD in the small gap between the housing and the rotating **** for the AUTO and LOCK function. This area gets dry and is the reason its hard to rotate. Turn the **** and you should see the diaphram move. Clean all of the parts, and relube and then reassemble. With the hub reassemble turn the selector **** from AUTO to MANUAL and you can see the manual operation pushes the diaphram inward which locks the hub. In the auto position the vacuum pump does the same. For the amount of time it takes to remove, clean and lube the hubs it is well worth it. Unless something breaks internally I'm not sure why people don't like these hubs. Hope this helps.

 

Let me say this again:

My ESOF hubs were locking or unlocking at the most inconvenient times, 1 year after I bought my '01.

I decided to just lock them when I wanted to use 4x4 and I went another year. Even when they locked after they should have been UNlocked.

After that, I took apart the hubs, and they looked PERFECT inside and were perfectly lubed.

Too bad they DID NOT WORK even though they were lubed and seemed to be working properly - and no, I had no vacuum leaks or other component problems, everything checked out fine.

Now do you understand why I have a bit of animosity towards my ESOF hubs?

art k.