First of all, let me say that as a new member to the site I have found the posts here quite informative. I have already discovered quite a bit about the problem I am having with my truck, but I still have a couple of questions I am hoping you can help me with.
My truck is a 2000 F250 with a 5.4L, auto trans., and ESOF 4x4. The front hubs are automatic with a manual overide. The problem seems to be that the automatic hubs are not always engaging. On a steep boat ramp, with the ESOF engaged in 4W high or ow and the hubs in auto, the rear wheels spin and I can detect no pull from the front. This has happened now a few times. The first time it happened, the dealer replaced the vacuum actuator. When it happened again I returned it to the dealer. This time the dealer said that they could find nothing wrong with the 4 wheel drive, and that they believed it was working properly. To make a long story short, I went to the ramp again this weekend and the same thing happened. This time when the wheels began to spin I got out and manually locked the hubs. The truck pulled right out! After leaving the ramp, I played with the 4wheel drive shifting in and out of the different settings. Although it is difficult to say with absolute certainty, the auto hubs did seem like they were engaged at times, but not at others.
From reading the posts here, it seems that failure of the auto locks is a somewhat common problem, and I have already learned a lot. The questions I still have, however, are;

1. Is it possible that the auto-hubs could be engaging only some of the time?

2. Many people have written about converting to manual hubs - my question is why convert to manual hubs if a manual lock already exists?

3. How can the dealer acurately test whether or not the 4 wheel drive system is working as advertised?

I know this is a long post, but I want to be fully prepared nest time I talk to the dealer. The truck is under warranty, so they are going to have to do any repairs. Any help/advice you can give is appreciated. Thanks for the help!

 

[updated:LAST EDITED ON 05-Sep-02 AT 10:15 AM (EST)]I have manual hubs so I am not sure about this but, I think the truck has to roll forward some after the switch is flipped to get the hubs to engage. If this is not right I am sure I'll be corrected. Welcome to the site.

 

Wheels is correct.

If you were not able to move forward at all after flipping the switch to 4X4, the front hubs will not engage. They require some rotation.

Next time try engaging the 4X4 before you back down the ramp. The rotation will allow the hubs to auto engage and your 4X4 should work just fine.

If not, then you have a problem with the hubs that is likely vacuum related. Check to make sure all the vacuum connections are tight and sealing. If you have further problems, give us a shout.

Waxy

 

drat read my results on pg. 16 of the archives under Im Baaaaaaaaaaaaak Report on 4wd lockin. I had a major problem which was related to the fuse block that was supposed to be installed on the firewall at the factory. It was not and was hanging down in the mud and crud. As far as vacuum assist on the auto lock I dont think that it exist at least on my 2000 CC psd it does not. Mine is fully electrical with a drive motor that locks the hubs in place.Hope this helps

 

Thanks for the replies guys. I always put the truck in 4wheel as I am backing down the ramp. I have also tried pulling foward and had the hubs not lock! I going back to talk to the dealer on monday, I'll let you know what I find out.
I had been hoping somebody would talk about why I should change to manual locs when I already have a manual lock from the overide?
Have a great day!

 

I had a problem last winter with may auto hubs not locking in, but when I locked them in manually they worked. I have the front hubs repacked for grease and they worked just fine. Yours could be getting stiff and may need repacking.

 

I just ordered a truck (see my signature) and I am brand-new to pickups and 4WD.
Is there a simple test that one can do to check operation of the front drive? Other than finding a boat ramp.


On order: 2003 F350 Regular Cab XLT 4WD V10 6-Spd 3.73LS

 

[updated:LAST EDITED ON 06-Sep-02 AT 11:15 PM (EST)]>I just ordered a truck (see my signature) and I am brand-new
>to pickups and 4WD.
>Is there a simple test that one can do to check operation of
>the front drive? Other than finding a boat ramp.
>
>
>On order: 2003 F350 Regular Cab XLT 4WD V10 6-Spd 3.73LS

First of all there is a good chance that the hubs will be locked when your truck arrives.Judging by previous posts it seems that they are delivered that way.No big deal as long as you don't engage 4wd.on the street and drive like it's in 2wd.If they are locked and you are in 2wd.you may notice a slight thumping when the wheels are at full turn while moving slowly in either direction,it's perfectly normal if the hubs are locked.

As far as checking whether or not your front drive is working ,(it'll work,I'm sure)you can engage 4wd at the lever or dial,depending on which method of activation you have,and drive forward slowly and turn the steering wheel.If everything is locked up like it should you will feel some binding and the steering wheel will want to cycle back and forth a bit.Don't get carried away and drive it this way or turn the wheel at full lock and continue to drive the vehicle,because for one it's not recommended and the driveline will be in a major bind because of no slippage between the front and rear driveline.In other words as soon as you feel any binding in the driveline when testing,stop,disengage 4wd.back up a foot or so,then put in forward gear and you'll be ready to drive regularly once again.

Hope this helps.

BTW,your truck is optioned a lot like mine,(except I'm cheap and have an XL.)
Enjoy your new truck when it arrives and if you have questions be sure to post them.There are lots of people here willing to give you the scoop.