Alright, so a new front end problem rears its ugly head. I need to ask a few questions before i go on ranting and raving.


2004 F250 FX4 No mods besides 4in exhaust and some gauges.





Electronic 4wheel drive ("On the Fly"): Why the heck do i have locking hubs if its "On the Fly???" I read the owners manual on it but it still isnt clicking with me i guess. When i lock it in 4WH there doesnt seem to be much of a change and i cant really tell if its actually locked in. 4WL..... throw it in neutral and click it over. Locks in perfect and you can definitely tell its locked in but there seems to be a lot of slip in the front end. Same when im in 2wd. If im at a light and get on the gas normal it doesnt feel like it hits hard until after youve began rolling a few feet and then it slams, like it has a lot of slip. So, all in all im guessing one of the 14,000 ujoints are going out. Anyone else have any suggestions or can tell me why the heck ive got locking hubs on the front!!


(This is the newest vehicle ive ever owned and to put it simply id like to have my 4wheel drive lever on the floor. I dont trust that switch.)

 

u joints make a popping noise. put in 4 hi in grass hold it wide open if you hear a bang pop etc u joint. more than likely its probably the vacuum seal inside the hub. Collapse the knuckles and install a new one. Get some ford 7.3 oil pan gasket maker (grey silicone) and put a little around the new seal (never know how long they sit for on the shelf in a parts room) when i say around the seal i mean the part that presses into the hub itself. the outside of the seal.

check and make sure the vacuum lines comming off the hubs arent broken. But if that were the case, there wouldnt be ANY 4x4 opperation (most of the times) BTW fords dont have posi fronts. At least i havent seen 1 yet...

 

Put in 4wh and turn the steering wheel to one side. Drive it in a circle and see if it crab walks.

 

The ESOF dash switch causes the vacuum motor to lock the hubs and transfer case motor to actuate.
The manual hubs are to provide a backup to the ESOF (Electronic Shift On the Fly) switch. Ideally the ESOF works every time causing the hubs to lock correctly. IF you were to discover the hubs were not locking (say due to a leak)you can turn the dial and lock in manually.

 

Not sure how ford is but my chevy was shift on the fly, 2h-4h at any time, 2h or 4h to 4L was under 15mph and in N, mine had limited slip wet disks in the front end. If yours doesnt have auto hubs then it isnt going to lock in the front end, shift on the fly will just engage the front drive, then if you need to lock it in full time you have to get out and set the timer(lock the hubs). Otherwise without locking the hubs it will just hook up caddy corner. Your problem almost sounds like your tranny isnt starting out in 1st because you said it does it in 2h as well. Every transmission I have ever owned felt the way you described when I would try to start out in second like if I down shifted and then forgot.

 

Alright, when i have it just in 2wd and drive in a circle or make a sharp turn there is a distinct knocking in the front. The only way to describe it would be it sounds like the front drive shaft is hitting something as it spins. Its like bang bang bang bang. Only does it when i get on the gas.

 

That sounds like a driveline but a driveline doesnt cause slipping, it either works or it doesnt, could be a supension problem, could be a knuckle at the hub, could be a hub. Lift it up so the front end is off the ground and grab a bar, try to pry the wheel up and down and side to side, see if there is any play anywhere. Does it "crab walk", (jerks back and forth when turning in a tight circle)? Does it matter how fast you are turning, slower speed slower knock? How far in between knocks, 1", 1', 5'?

 

It doesnt crab walk at all. The faster i excel through the turn the faster the knock gets. Im doing all u joints today to scratch that off the list. Ill see if there is any play in the front tires and if so i plan on doing the knuckles possibly hubs. Thought about pricing those today anyway. Ill let you know how it goes thanks for the help.

 

I've broken the hubs themselves before on my rangers, not on this one...yet. The splined shaft would spin inside the hub. They were not cheap to replace, but I went with Warn units. Have someone stand outside the truck and try to pinpoint where it's coming from.