One thing I forgot to mention.

If you guys are going through such rough stuff, then why aren't you in 4x4 before you go in ?

I don't think ESOF will turn off or make 4x4 fail quicker than the manual method. It doesn't require voltage or vacuum to remain in 4x4.

The problem is getting it into 4x4 in the first place, but once it's in, I've left it in for weeks and never had a problem.

 

The hubs won't stay locked without vacuum will they?????

 

From what I know of the system, you don't need constant vacuum to retain hub lock. It's a toggle of some sort.

Can anyone else confirm this? I'll go digging for it myself, too...

 

Lookie here!!!

HUB LOCK OPERATION

The Super Duty and Excursion 4X4 ESOF system uses timed vacuum sequences to lock and unlock the wheel ends. A high vacuum level is used to engage the hub locks, and a lower vacuum level is used to disengage the hub locks, after which the vacuum is released and the hub lock holds itself in the proper mode. The vacuum signals are supplied to the hub locks by system components, including Generic Electronic Module (GEM), wiring harness, solenoid, vacuum harness, and vacuum seals. As a first step in service, eliminate such obvious items as loose wiring connections, loose vacuum connections, or damaged vacuum lines.

DISENGAGE TIME

"Slow" release of the hub locks is not considered abnormal for this system. Anytime vacuum is applied to the hubs, whether for 4X4 or 4X2, the hub locks will initially engage. If 4X4 was requested, they will remain engaged, but if 4X2 was selected, the internal mechanism will release only after the GEM timers expire and vacuum is vented from the hub. This normally takes 15 seconds, but can take up to 2 minutes depending on how the 4X4 mode switch was operated. After the hub mechanism releases, internal springs must work the hub lock gears to the disengaged position. Road bumps, vehicle speed, acceleration cycles, or momentary reversal of direction can assist this process, varying the length of time the hub locks remain engaged in each situation.

 

when I bought mine the 4wd wouldn't work,dealer cut me a hell of a deal. traced the wires from the shift motor to a set of relays under the hood thats bracket had been installed upside down causing the water from the dealer washing of the motor to corode making them inoperable.Stupid STEALER!!!!! Ha,Ha,Ha

 

heres the way it stands right now. the dealer is making a trade with another dealer for basically the same truck but with manual 4x4. dark green F350 r/c manual 4x4 xlt 6.0l. should be getting by friday.

 

Sounds goooooood

 

I would not let esof be a deal breaker either. I have not had any trouble with mine esof system. I probably only use it 8-10 times a year and I don't do any "exercising" of it either. I will say, however, to be sure to READ THE INSTRUCTIONS; I thought that I was having trouble with it not shifting from 4-hi to 4-lo, but turns out that I was not fully pressing down the clutch pedal, which is a pre-condition. I think the vehicle also must be fully stopped to shift to 4-lo. But even with a lever transfer case you are supposed to stop to go to low, but you can do it if you want (GRIND!)
mike

 

lugnut it was a deal breacker thats why he's making the trade. esof is a liability to my way of thinking. and a chance i am unwilling to axcept.

 

Has anyone almost shifted on the fly while just going to turn on the fan? I almost did that the other day, reached to the fan **** without looking, but luckily I looked down before turning the "fan" on, or else I would have been in 4wd at 75mph.

 

HEy?!Why's my u-joint flying around in the air like that and what is that noise from the t-case?!

 

I've done that in the rain, and no harmful effects. Done it in snow too, and then went onto dry pavement, a little more whine from the gears, but again, no broken parts.

I think the servo on the transfer case should have a crank handle though

On another note: so the hubs do NOT disengage if vacuum is lost. So, going into rough terrain, put it in 4x4 before going in, and it will stay in 4x4.

In my case, I would NOT have gotten ESOF except that it was already in a truck that I got a great deal on - unlimited milage 4-year lease (Ford Red Carpet) and $9K buy-back at the end of the 4 years. I can easily make money on it by turning around and selling it.

 

No, that's not correct.If vacuum is lost the hubs WILL disengage.

 

That's not what the post above says, apparently quoting an owner's manual or other Ford source.

I'm ready to go out and put a vacuum gauge on one of my hubs to find out now...

 

krethats a great deal on a lease we are getting taking to the cleaners right now on mileage on f150 33000 over. where talking almost 7k.