First off: Hello. I just got a "new to me" used 2001 F250 5.4 L, 4x4 and I'm loving life. No one honks at me or cuts me off . . . maybe it's because I had to drive the minivan for a while that this is even something I appreciate

This board is just great, no man drama, just guys showing off and helping out, I can appreciate that!!! Did some fluids already just to get on my schedule, oil change (diggin' not having to jack it up), new rear diff. cover and new fluids, new fluids in the front diff.

Here's where I need some help: I was going thru the motions and testing everything out and the 4x4 doesn't seem to kick in. I turn the ESOF switch to 4H and I hear a little click. The light turns on, but the front hubs don't lock. I can manually lock them and 4x4 works great, but when I use the switch, nothing seems to happen.

What I've done so far: I took apart and cleaned/greased the locking hubs. They were pretty clean and the **** turns easy (seems like the old owner took care of the hub locks). I read on the board about ESOF issues but nothing is quite the exact same problem as mine. My A/C and Heat work fine, they don't default to the defront setting (so I think it's not a vacuum issue). I checked all the plugs and harnesses on the transfer case, they seem good. When I click to 4L, it goes "thunk" and I think that's what it's supposed to sound like. Am I missing something? I really would appreciate ya'lls help.

 

It sometimes takes a little movement to get the hubs to lock, but I'll assume since you know it works manually that you drove it a short distance to see if it engaged.

I had problems with mine this past winter and didn't notice the defrost problem, but when I checked the vacumn hoses to the wheels one of them was cracked and leaking. I replaced the hoses and everything was fine. As cheap and easy as the hose is to replace you might try that. They just pull off.

 

yea start with checking the rubber hoses going to the steering knuckles..

make sure you have vacumm there..

 

Thanks, i'll check that first thing tomorrow. I'm hoping it's an easy fix like the hoses and not something expensive. I'll update and let you know.

 

Just my .02, I have a 2009 F250 4X4 CC LB. When i engage into 4L yes I here a thunk or a clunk, and yes according to the manual thats what it will do. Now when I engage 4H, I here a little click my 4x4 light comes on and blinks (which means not engaged) The manual states that you should be going at least 5 mph to fully engage 4H. So I do 5 mph and it engages and the 4x4 light is now solid. ( you are suppose to be stopped to engage 4L). In reading your post you sound like you know your stuff. I just thought I would send my .02 about what I read in the manual and my experience with the 4x4 system.

 

Thanks again everybody. Looks like it's gonna be a bit involved. I put my mityvac vacuum tester to the various hoses, and looks like the hubs aren't holding vacuum. The hoses, as worn and as crusty and cracked they look, actual hold vacuum. When attaching the vacuum to the nipples on the hub, it doesn't hold vacuum so it's gonna be one of those 3 orings or something. I think I'll wait till spring to tear into em' though. If anybody thinks it may be something else or I'm testing it incorrectly, please let me know. Again, thanks for your help fellas . . . now, on to search for an answer to the death wobble, scared me to ess, h, i, t today.

 

Look up Guzzle's R&R for the needle bearings etc. If I remember right you can replace the o rings when doing that. It isn't that bad of a job. My biggest problem was getting the hubs out as one had a bunch of rust that kept if from pulling out.

Also, the death wobble can be a lot of things. On mine I had frozen caliper pins that were causing the brakes to drag and that caused mine.

 

Here is the guzzle site for the needle bearings. He has part #'s and torque specs on there for the o-rings and stuff you need. Welcome to guzzle's 4x4 Needle Bearing Maintenance Web Page

I do this once a year, plus the caliper slide pins, so it now takes WAY less time than the initial first one. Put aside 2-4 hrs per side if it is your first time. Tires off to tires on including the esof hub and slide pins.

 

The vacuum ESOF system for locking the front hubs leaves something to be desired. A good idea in theory has not translated well to the real world. Many of us have experienced this. I am on my second round of leaks after replacing EVERYTHING from the solenoid to the locking hubs. I'm close to just buying some Warm Premiums and capping off the lines.

Below is a link to a lengthy thread of troubleshooting. In post #7 is another link to the troubleshooting I did the first time around to give you a start.

https://www.ford-trucks.com/forums/8...-engaging.html

To keep things running tip top in the front drive system, you should engage 4wd at least once a month for a while to cycle everything and churn up the liquid in the transfer case and front diff to keep it working as best as possible. I learned the hard way since I don't think the guy I bought my truck from had used 4wd in years.

Hope this helps at least some.

 

If you decide to wait until spring to deal with the hubs you can leave them locked in the winter and just click in and out of 4 as you need to just try to avoid cranking the wheels fully to either side