I've been reading the archives, some useful information I'm going to check out, but for a fresh view and since it is an '02.

My ESOF 4x4 is inconsistent. It has acted strange, slow to engage, lights not coming on quickly since I got it, but it's always worked. Until this morning.

This morning, shift to 4x4, no light, 4x4 low, no light. So I hook up to pull out anyway, I leave it in 4x4. I can tell it's NOT engaged.

As I climb the hill I hear a clunk and stop moving, the front left tire is spinning and both rear tires are "walking". I stop... and notice the 4x4 light is on. As I slowly move and have my wife looking around I figure out the front right is NOT engaged.

I manually lock the hubs, still no front right... it has too roll to engage, so I back up and start again and sure enough I have 4x4 instead of 4x3 and start climbing. I stop, try 4x4 low, it too works.

After stopping, I switch to 4x2 and all seems well, I disengage the manual locks everything seems fine.

Later that day I decide to do a bit of checking, I turn on 4x4, light comes on goes to 4x4 seems just fine. Though I admit I have no sure way of knowing if it's 4x3 or 4x4 except, in a sharp turn the front "walks" on pavement. I'm guessing in 4x3 since one wheel is free it wouldn't walk. 4x4low works too. So... I turn it off and go to park... and the front is still walking, I try for 5 minutes, driving, turning, stopping, reverse I even drove off into the grass... still in 4x4 but the light is off... not sure if the xfer case is engaged... would the wheels walk if it was not?

So I turn the truck off, the next time I crank it, about 4 seconds later "clunk" I check it out and the 4x4 is disengaged.

I've check, rechecked all the connections and wires under the truck, they all look fine.

So, after that long winded post...

From experience and from the archives, I can deduce/infer my hubs are not locking automatically, at least not consistently. What I saw was a failure for the right to lock even though the left did.

My transfer case may or may not be engaged, not sure how to tell, any help would be great.

Would the front end still walk with the hubs locked and the transfer disengaged?

Can anyone shed some light on what I might need to kick or tell the dealer to fix?

Thanks,
Robert

 

I'll try to help some.I'll try not to confuse us.
In 4wd. if one of the front wheels loses traction then all power is sent to the slipping wheel.
When in 4wd.and turning the front will tend to bind and steer funky no matter if one wheel or both wheels have limited or a lot of traction.This is because the front and rear wheels are traveling different speeds due to different turning radiuses between the front and rear wheels.The front and rear wheels are directly connected to each other through the transfer case.There isn't anything to "differentiate" between the two different axle speeds so the tires are the weak link and that's where the axle bind is released(through the front tires).

I have a manual transfer case,but this may apply to electronic shifted ones also.If I'm cruising down the road with hubs locked and shift into 4hi then I'm in 4wd.After cruising for a while and lets say I put the transfer case shifter back in 2hi while moving and the throttle is still applied then I'm theoretically in 2hi.But until I let off of the throttle and decel a little bit the truck is still pulling as if in 4hi.(Some may say I'm FOS but this is what I've found through the years)

I hope this addresses some of your questions.
IF not,disregard it.
I had a hell of a time explaining this and I'm not so sure I helped.
But I tried.

 

>From experience and from the archives, I can deduce/infer my
>hubs are not locking automatically, at least not
>consistently. What I saw was a failure for the right to
>lock even though the left did.

I agree- it sounds like one or both hubs aren't working properly.

>My transfer case may or may not be engaged, not sure how to
>tell, any help would be great.

I'm not sure if the front driveshaft rotates or not if the hubs aren't engaged. Someone will surely know and educate us.

>Would the front end still walk with the hubs locked and the
>transfer disengaged?

Yes.

>Can anyone shed some light on what I might need to kick or
>tell the dealer to fix?

First thing is to have them check both front hubs. You'll probably have to duplicate the problem for them if you can. Otherwise, just tell them the story you told us.

 

[updated:LAST EDITED ON 09-May-02 AT 08:20 AM (EST)]Hmmm... I'll have to demonstrate this for them
I can guarantee it'll work perfectly as soon as I hit the lot, I think it can smell Ford Dealership Pavement.

From the replies, I think it is the front hubs failing to lock and unlock properly.

Let me make sure I know the correct answers to these questions before I go demo my truck...

Hubs to Auto, truck in 2WD:
The most important question, should I be able to rotate the drive shaft going to the front wheels? But with locked hubs I should not?

If I raise one side of the front, I should be able to spin the front tire, as if it's on a spindle? Of course I should.

If I raise the front, both wheels should spin freely. If I then engage the hubs to manual, I should get both to lock and have one tire cause the other to counter rotate?

Hubs to Auto, truck in 4WD ( after engaging it with the truck running and moving around )

I raise the front, I should spin one tire and cause the other to counter rotate? i.e. it should behave just as if the hubs were manually locked?


Thanks,
This is a great board, I try to contribute when I know something and appreciate all the others that do too.

Robert

Oh, one more question, I was under the impression that when in 4x4 low the front wheels were locked together and no tire could spin faster than the other, like a posi lock, is this true or false?

 

The front end does not have any type of locking or limited slip differential. Only one wheel will spin at a time. If you want both fronts driving at the same time you need to install a locking differential (most folks use an ARB air locker). Driving with a locked front differential (or locked rear for that matter) is very hard on the drive train if you are on pavement and it can be dangerous in turns since it forces all wheels to turn at the same speed. The inside wheels will want to turn slower than the outside wheels ( they are travelling less distance so fewer revolutions) which leads to internal twisting of the shafts.

It sounds to me like the worst problem you might have is a slight vacuum leak which is causing a delay in engaging the 4wd.

 

>It sounds to me like the worst problem you might have is a
>slight vacuum leak which is causing a delay in engaging the
>4wd.

After reading everything, I agree with MartyB.

 

>From experience and from the archives, I can deduce/infer my
>hubs are not locking automatically, at least not
>consistently. What I saw was a failure for the right to
>lock even though the left did


I agree with MartyB, I don't see any problem with the way your 4X4 is operating. The scenario you described sounds like everything is working as it is supposed to. The right hub was locked, but power was not being sent to it. The front diff is open, so the power will go to the wheel that is easier to turn/free spinning. You must have a limited slip in the rear diff, or you'd find out that your truck is really a 4X2!! 4X3 is the best you can hope for without aftermarket lockers or limited slip installed in the front axle. I wouldn't recommend that unless you do a lot of offroad driving (the ARB would be the best option, since when disengaged in acts like an open diff).

The binding is due to the transfer case engaging and locking the front and rear axles, as 4X4X4X4 described.

>I'm not sure if the front driveshaft rotates or not if the hubs >aren't engaged. Someone will surely know and educate us

The front driveshaft will rotate (under engine power) if the the transfer case is engaged, regardless of whether the hubs are locked.

>The most important question, should I be able to rotate the drive >shaft going to the front wheels? But with locked hubs I should not?

Yes


>If I raise the front, both wheels should spin freely. If I then >engage the hubs to manual, I should get both to lock and have one >tire cause the other to counter rotate?

Yes

>Hubs to Auto, truck in 4WD ( after engaging it with the truck >running and moving around ) I raise the front, I should spin one >tire and cause the other to counter rotate? i.e. it should behave >just as if the hubs were manually locked?

No. You should not be able to spin the front tires if the transfer case is engaged (in 4WD) and the hubs are locked. You'd have to be strong enough to spin the rear wheels as well.

Hope this helps.

Waxy

 

That helps, I now have a way to tell if the hubs are locking and if the transfer case is engaging etc...

If I put it into 4WD and let it engage, then raise the front end... if I can spin a wheel freely, but not the drive shaft, no hub lock xfer case is locked. If I spin a wheel and the other counter rotates, no transfer case lock. If I successfully spin the wheel with locked hub and engaged xfer case nothing is engaged or I'll be roll starting the engine :-)

Sound like a vacuum issue... so any suggestions what I should look at? Sounds like a mechanical issue rather than an electronic and I'd love to avoid the dealer if possible, I suppose a hose could be loose.

Robert

 

To be honest I wouldn't put too much effort into it. Since you have ESOF, you can always manually lock the hubs if you need instant 4x4.

One trick- if one of your wheels (front or rear) is spinning, a little brake pressure (left foot real light) will tranfer torque to the other wheel

 

The thing that is bothersome is the first sentence in the fifth paragraph of the original post... "I manually lock the hubs, still no front right." Seems that hub is sticking open when either vacuum or manually engaged. If so, then it needs to be checked out.

 

>The thing that is bothersome is the first sentence in the
>fifth paragraph of the original post... "I manually lock
>the hubs, still no front right." Seems that hub is
>sticking open when either vacuum or manually engaged. If
>so, then it needs to be checked out.

Nomo,

It would seem to me that if the left front wheel in this situation was spinning freely as described, then the right front not spinning was due to the open differential. I believe that the hub was locked the entire time, and that operating the manual override was really inconsequential.

A quick check with the front end elevated will determine if the hub is locking properly.

Waxy

 

You are probably right. But he goes on to say that after backing up then taking off again, it worked. Guess it could be attributed to "torque-binding", but I don't like it either way. IMO, the hub engagement should be solid, but smooth.

 

[updated:LAST EDITED ON 09-May-02 AT 06:15 PM (EST)]If the left front had more traction on the second attempt, that would cause the right to spin freely and appear to be working correctly, it's hard to tell from inside or without watching both wheels what's going on.

I shouldn't say I'm 100% certain on this, I've noticed that the engagement of my hubs is far from what I would call smooth, especially in a sitauation where I'm already stuck or where there is wheel spin. The front hubs can be a little lazy in reacting. Like you, I'd like a firmer, yet somehow smoother, lock up. A more "positive" transition.

I guess if I wanted super smooth I'd get a Subaru or an Audi

Waxy

 

You are all right... that's why I wanted to be clear about how this works. I was under the impression the 4x4Lo locked the fronts together, thus when the front right was not spinning it lead me to believe it was not locked.

But if it actualy was not locked, that might be the whole reason I got stuck in the first place, and that was with the auto switch.... but if the diff does not lock... the right wheel axle would have been free to spin and the left would....

ahhh heck, next time I'll let my wife drive while I video tape the action.


Thanks, it has helped.

Robert

 

If one of the front hubs isn't locked then the power will be sent "wasted" to this axle shaft and no power will be transmitted to the ground until it is locked also.

This scenario may help also....A few years back I parked my 96,manual hubs manual transfer case on solid ice and was in 2wd.at the time.When I left I first locked the hubs and then shifted the lever into 4wd.I started the truck and tried to pull forward,low and behold it seemed to still be in 2wd.I let off the gas and then goosed the throttle a bit the truck moved forward slightly and then all of the sudden the front wheel(s)started pulling like they were supposed to when in 4wd.I may be wrong here but I believe the hubs may need to see a bit of forward movement from the wheel to initially lock when placed on 4wd.That's what I've always assumed since the day this happened to me in my 96 model.