I have 99' 1/2 F250 4x4 turbo and never got a operators book with it.

1) It has a switch in the dash for 2x4, 4x4 high and 4x4 low. At the hubs it has a dial that can either turn clockwise or counter clockwise. How do I operate the 4 wheel drive, how do I set it/change it ? I assume I put the transmission in neutral before I turn the switch in the dash but where do the hub dials get turned to? I cannot see a direction of the hubs.

2) Front axle differential fluid - how much does it take? What type of fluid? I am getting different answers if I call different ford service areas. One says because the tag on the rear axle says I need the expensive synthetic that I need it in the front even though the front has no such tag. Another says they use 90 weight in the front even though the back uses the synthetic. I don't want to use the expensive stuff if I don't have to but at the same time I don't want to ruin the differential either.

 

I am guessing a mobile 1 synthetic 80W90 would work fine based on the differential fluid thread below. Am I right? I found out that it takes six pints just like the back.

 

1) with the electric transfer case you can use the 4x4 one of two ways. you can either lock the hubs in manually (turn clockwise to lock the hubs and counterclockwise to unlock) then turn the switch to the position you want; if you go from 2wd to 4hi or from 4hi back to 2wd you can do it either stopped or on the move. If you want to go in or out of 4lo you have to come to a complete stop, shift the transmission into neutral, then turn the switch to or from 4lo. Also, the electric transfer case allows you to use the hubs as autolocking when they are turned counterclock wise to the unlock position, then all you have to do is turn the switch to the position you want it(2wd to 4hi or back can be done on the move or stopped, and to go from 2wd to 4lo or back you have to stop and shift tranny to neutral first). I personally would use the hubs as manual locking instead of using the auto feature; auto hubs can't hold up to hard use like manual hubs can, and auto hubs have a tendancy to unlock if you have to rock the truck to get unstuck. If you use them as manual hubs you can lock them in and leave them if you think you might need 4wd. They can be left locked in for extended periods, but having everything spinning all the time will cause more wear and tear on the front end and you fuel mileage will drop some. Also, don't drive in 4hi or 4lo on a dry hard surfaced road because it will cause driveline damage.

2) I don't know how much your diff. holds because I have a 1/2 ton and the axels are different sizes. On mine I believe it uses synthetic in the rear and regular in the front. I would get your dealer to order a manual for you it shouldn't be a big deal for them to get one

 

Thanks Fordman!

 

Your truck has ESOF. That's Electronic Shift On the Fly. The hubs are vacuum activated. There are vacuum lines running to the hubs that locks them when you put the dash switch in 4x4. The hubs don't have an "unlock" position. They have "auto" and "lock." You only need use the "lock" position if the vacuum system fails. When it works they lock just like manual hubs. They are not like the older auto hubs that unlock and re-lock every time you change direction. I had those on my 96 and they sucked.

 

On the fluid for the front diff. It takes 85w-90, dino or synthetic(your preference). 3 quarts should do it. Just keep filling it until it leaks back out of the hole. Then put the plug back in it is very simple.

 

I have a question. Normally I would post it seperately, but you guys were discussing it so I'm asking it here. Hope no one minds. Just purchased my first full size p/u. Been driving a Ranger I bought new in 88.(305,000 miles). 2000 F-250, XLT, 4X4, PSD, 6 Spd. Regarding the locking of the hubs, mine has the "auto" and "lock" position. The question I have is when I am not in 4 wheel drive, are the front wheels free wheeling or is the whole front end turning?

 

If you have ESOF - go by what RRMike said above. Leave them in "auto" and they will disengage whenever you turn the ESOF switch back to 2WD. The hubs will "free-wheel", the axles will not turn and the transfer case will be disengaged, causing the driveshaft to stop spinning.
If you have the manual (shifter in the floor) for you transfer case, then more than likely you have the locking hubs and you will need to lock/unlock as you use them.

 

If they have "auto" and "lock" then you have esof. When they are in auto they are unlocked. The front drivetrain should not turn. You might want to visually verify this as some of the rigs with esof have problems with the hubs staying locked even in the auto position after the switch is turned to 2wd and wearing out front drivetrain parts. If you put it in 4x4 on the dash it is designed to lock the hubs by vacuum and you don't have to get out and do it. If you ever have problems with it not engaging the front end it's probably the vacuum system and you can get out and lock them manually.

 

After reading these post, I think I may have a vacuum problem. I have a 2000 PSD with the ESOF, auto and lock hubs. If I turn the dial to 4lo, it will light up on the dash but will not fully engage, so I have to lock them in manually. My truck has 81,000 miles, if it is a vacuum problem, would it be covered under warranty?

 

Not at 81k unfortunately. That is unless you've purchased some kind of aftermarket warranty.

I don't know much about the workings of the esof so I'm sorry I can't give you a great deal of help. If you post this in the superduty forum there's tons of guys up there that know about how this stuff works.

 

Thanks for the responses. This is a great site. I get better answers and more help here than if I call the dealer.

 

I have a question regards engaging 4WD on a 2003 F350 CC with manual locking hubs. I have the "old fashion" floor selector for 4WD Hi-Low and 2WD modes. The owners manual states that the once you lock the hubs shift in to 4WD Hi you can change back into 2WD at speeds up to 55 MPH. Is it safe to shift back in to 4WD HI while driving or do you have to stop in the middle of the highway to re-enagage 4WD Hi?

Thank for any help...

 

Yes, you should be able to shift either direction as long as the hubs are locked in. The reason is that the front and rear drivetrain should be turning at the same speed so no problem. If you've ever made the mistake of trying it without the hubs locked all that will happen is you will hear the gears grinding and it won't go. Don't try to force it. It should shift rather easily going into 4X4.

"Old fashioned!" If you do a search on the site about ESOF you'll probably see that the old fashioned way is considered by many to be far more reliable. There's nothing bad about the manual system.

In case you couldn't tell mine has the old fashioned manual shifter and manual hubs too It was a deal breaker for me. I wouldn't buy one with ESOF. IMO it's just more stuff to go wrong. When I need 4X4 it's the last time I want to be having problems with my truck.

 

RRMike,

Thanks!! That is what I thought but the saleman said you can only shift into 4WD Hi at speeds below 5 MPH and that seemed realy odd. Your answer is what I expected.

Thanks again

Howdi.