Ford Auto Hubs can cause spectacular failure

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I had quite an experience coming home from vacation this year, and I'd like as many people as possible to be aware of the problem, and how to avoid it.
Briefly, the automatic front hubs on my 2000 F-250 failed, and were stuck in locked position. This happened once before, and the hubs were replaced (10k miles and well over the 12-month warranty period). This places a lot of stress on the drive train, and in my case the CV joint (on the front axle) failed. This caused the crank-case and transmission to literally explode, sending chunks of metal flying all over I-80 in Wyoming. One chunk, in fact, struck the under-side of the pontoon boat I was towing; had the boat not been there, it might have been somebody's windshield.
This pickup has almost always seemed to bind in turns. I was aware that this happens in 4wd (no positraction up front, which is normal). I was not aware that the hubs might be stuck, nor was I aware of the potential consequences. Since the dealer had told me everything was OK a couple of times I complained, I just assumed that was the way the pickup drove. Wrong!
From the Internet searches I have done, as well as talking to some repair shops, it appears to me that Ford's are especially bad for this. Apparently the hubs use some type of vacuum to disengage, and that's what people seems to fail.
What I would REALLY like to have happen is everyone with a 4wd pickup, with auto hubs, go out and make a couple of hard turns (cranked all the way). If there's any binding, and it kind of jumps through the turn, you should have the hubs checked immediately. If you want to know what the "feel" is I'm trying to describe, just put it in 4wd and try a hard turn or two.
Note that if your hubs ARE defective, a REALLY good thing to do would be to log it on the NHTSA's web site. You can file a complaint here: http://www-odi.nhtsa.dot.gov/ivoq /
If enough people do that they will investigate, and potentially issue a recall.
What I did (besides "invest" $5,500 in a new crank-case an tranny) was to replace the Ford hubs with Warn manual hubs. I will never have the same issue again -- besides, the Warn hubs are a lot cheaper.
For Ford's part, they have taken the stance that all parts are out of warranty (which is true), so they have no financial responsibility. I feel that NO vehicle should EVER scatter metal on a highway (an opinion also expressed by the NHTSA investigator I talked to), and that Ford should acknowledge that and at least help me out. I'm probably going to see how hard they decide to fight me in court.
I would be VERY interested in hearing from anyone else that's had their hubs fail to unlock (or lock, for that matter), especially if it caused additional problems. I created a yahoo account just to keep replies separate, and would greatly appreciate any feedback or ideas.
Rob ( snipped-for-privacy@yahoo.com)
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Hmmm.
2004 Explorer automiatic with 4WD, 97 Mazda B4000 5-speed 4WD.
Don't use the 4WD on the Explorer very often but the B4000 4WD gets a lot of work. Never had a problem with hubs except that now and then the Mazda goes "zzzzzzz" when the front hubs don't release -- drive about 10 feet in reverse and they release.
Still, I'll go out and do a few hard turns in both 4WD and 2WD at slow speed and at as high speed as I dare to see what happens.
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Explorer does not use the autolock hubs on the Super Duty.

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Hmmmm. Okay. I'm not sure what that means or doesn't mean. I'm NOT an expert on 4WD.
This is what I have always done: -- Don't use 4WD on hard-surface roads, or on dirt or gravel roads where the vehicle is humming right along in 2WD. -- Use 4WD ONLY when the vehicle is spinning the wheels or not pulling in 2WD. As long as 2WD is moving me along, I stick with it. -- Every so often -- about every six weeks or so -- I get onto a rough, uneven surface -- I use a nearby road with loose gravel and a steep uphill grade -- and go into 4WD for a short distance to keep the hubs, etc., lubricated.
My Explorer has three buttons on the dash -- 4AUTO (normal), 4WD LO, 4WD HI. My understanding is that in 4WD AUTO it will drop into 4WD or AWD automatically when the rear tire(s) lose traction then shift out when it's not needed.
With the Explorer in 4WD HI or LO (which I did a good bit getting around after Hurricane Katrina) the steering was "different" -- not difficult or anything but steering took a bit more effort that usual.
In my Mazda B4000, when it's in 4WD LO or HI, the steering is MUCH different, especially in a somewhat sharp turn. Is this normal?
Thanks.
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Super Dutys with electronic shift on the fly 4wd have autolocking hub locks which are supposed to spin free when the vehicle is in 2wd, but have a provision for manually locking in case of hub lock malfunction. Dial on the dash says "2Hi, 4Hi, 4Lo. Standard shift 4wd have manual locking hublocks that have selectable dials. Transfer case lever positions are 2Hi, 4Hi, N, 4Lo.
Explorers don't have any kind of hublocks, the front drivetrain is engaged but freewheeling when in 2Hi.
wrote:

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IKf you perform this test in 4WD on dry pavement, you should expect to feel binding and a wobble in the steering wheel. This is perfectly normal, and it is your sign that the 4WD system is not happy with the crap that you are making it do.
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message

I put the Mazda into 4WD HI on dry pavement, drove slowly about 20 feet straight ahead, tried to make a right-turn and the truck told me that was not the right thing to do -- end of experiment.
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OK, here's my feedback. You obviously don't understand how four-wheel-drive works.
Your transfer case (NOT crank-case) was in 4wheel drive on the interstate. That's what destroyed it. Just locking the hubs does not mean you are in four wheel drive, the hubs engaged and the T case in 2wheel drive means the front driveshaft is spinning, but just freewheeling. This is what happens to other makes (Jeep, GM, Dodge) which don't have front hublocks in their four wheel drive vehicles. If the hubs fail to unlock, it doesn't really cause all that much stress on the drivetrain.
I have had an F250 with the problems you described, but never had any catastophic failures. Granted, the vacuum operated autolock hubs are bad design, but the hubs alone wouldn't have cause your transfer case to explode. You must have been in four wheel drive on a high traction surface on a regular basis, which you should NEVER do.
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Matt Macchiarolo wrote:

Yes those auto hubs were pretty unreliable on my 95 f150 4x4. i replaced with warn manuals
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F150's didn't have the same hubs as Superduty, but I would agree with you in general, autolock hubs are pretty unreliable.

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I would agree with this. This is a very simple explanation, where the OP's explanation required a long sequence of events (made up, obviously) that don't seem to be plausible.
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says...

Everything falling to pieces appears to be rare. I definitely did not have the pickup in 4wd, and the only time I ever have driven it in 4wd on dry pavement is when pulling boat from the water, and I'm good enough backing I don't make any hard turns.
According to the guy that repaired my vehicle, as well as a Ford mechanic I talked to, driving that pickup over 45mph with hubs locked is a big no-no, and does cause a lot of stress. The owners manual stresses no 4wd over 45mph, but didn't say anything about hubs locked.
Rob
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Let me repeat: LOCKED HUBS DO NOT EQUAL 4WD. Unless your transfer case was in 4wd as well, there is NO WAY locked hubs could have destroyed your transfer case. Your transfer case was either in 4wd, or malfunctioning, or it disintegrated for another reason, but I can guarantee you it had NOTHING to do with locked hubs.
Driving with locked hubs with the transfer case in 2wd is PERFECTLY ACCEPTABLE at any speed. The 4wd systems made by Jeep, Chevrolet, & Dodge work this way because they are not equipped with selectable hubs. The front drivetrain spins all the time, freewheeling in 2wd, engaged in 4wd.
I drove around with my F250's auto hubs engaged for a week before I was able to take it in to be fixed. No problems. As long as the transfer case was not in 4wd, I was OK.
You seem to be under the impression that having hubs locked means you are in four wheel drive. This is not the case. Either you misunderstood what your mechanics told you, or they don't know what they are talking about. When I brought my truck in the first time, even the service guy was clueless...he thought I was in 4wd simply because my hubs were locked.
Driving with one hub locked and one unlocked isn't a good idea, but that wouldn't hurt your T-case either.
Matt

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As the CIA guy said to the President in the 4th of July movie.. Um, that's not entirely accurate.
If one hub were to lock in, and the other hub were to freewheel, you could blow up the center section. Not as easy certainly, but it will eventually fail. The differential will over-speed, a bearing will seize, and if you keep going with that noise, it'll likely have a gear fracture and send stuff out the side of the housing.
4wd systems are complex and I'm shocked at the number of 4wd systems on the road where people don't have a clue. the AWD systems are really what people that don't have a clue should be using. They are more expensive, but they require less thought.
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wrote:

That's not what happened to the OP. Also, I mentioned this scenario in a previous post as "not a good idea." And that's why when the left hublock on my own F250 failed to disengage, I manually locked BOTH of them so as to keep the center diff spider gears from overspeeding, until I brought it in to be fixed, which was PERFECTLY ACCEPTABLE at any legal speed.

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says...

Have been aware of that from day 1.

Transfer case wasn't destroyed ... same transfer case is still on the pickup, without any repairs. The crank-case (bolted to the front of the transmission) is what went. The constant-velocity joint on the front axle (between transfer case and crank case) gave out. Mechanic *said* that causes a lot of vibration in both the crank-case and transmission, and is what caused it to fall apart. BTW, Ford accepted the partial transmission as a core (crank-case doesn't have a core charge).

Could be ... Ford service manager told me not too, though.

Nope. Have had 4 4WD vehicles, two with manual hubs, one with semi-auto (explorer, had to back up to disengage hubs) and this F-250, which *claims* to not need backing up. Since taking it out of 4WD the day before, the pickup was in reverse, park, running and off.
The old auto-hubs, when taken off the vehicle, were set in "auto", yet were obviously locked (did not turn freely). After playing with one of them awhile (turning to "locked", then back to "automatic") it's loosened up to where it's hard to get them to stay locked. The other one is still rigidly stuck in locked, and I don't intend to touch it.
I appreciate all of the answers and discussion. I'm not a mechanic, but I am familiar with 4WD and the basics of how a vehicle works. From the responses I've seen this is obviously NOT a normal thing to have happen. Maybe the hubs weren't the cause of the failure, even though they were stuck in locked. I just don't know.
Rob
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The engine is bolted to the front of the transmission. The crankcase is part of the engine. It's where the engine's crank is. The top part of the crankcase is the engine block. The bottom part of the crankcase is the oil pan. What was replaced?
The constant-velocity joint on the front axle (between transfer

You really need to be more careful with your terminology, it's too confusing to try to interpret what you mean. The CV (double-U-joint) joint is not on the front axle, it is on the front driveshaft, on the transfer case end, not the end connected to the axle. The centering ball is in the joint on the transfer case end of the driveshaft. Did the joint completely let go and detach from the transfer case as you were driving, or was it still attached when the damage happened?
If the drivshaft joint was still together when the ball failed, any vibration severe enough to destroy the transmission would have been felt for a reasonable time before serious damage was done. If it came apart, there normally would have been some vibration & noise for a while as it was failing but before it came apart. It's hard to really pinpoint what happened, the way you tell your story makes it look like the story changes with every retelling.

He's a moron.
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Matt

The HUBS did not cause the failure. Clearly you had a failure that was catastrophic, but the hubs did not cause it. Something else caused it. Were it not for whatever that failure was, the front hubs can be locked 100% of the time and nothing bad will result.
Having the hubs locked, AND having something actually be wrong somewhere else can set up a problem that quicly becomes a catastrophy, but the hubs are not the cause. The cause is the other stuff that gave up.
CRANK CASE The crank case is the bottom of the engine. It is where the crank shaft lives, and all of the motor oil. The crank shaft is connected to the pistons.
The crank case is forward of the transmission, that is true. But the hubs would not destroy the crank case. The front drive shaft could (in theory) whip around violently and destroy the crank case, but that would be very noisey for a long time before the catastrophy happened. If the front hubs were locked AND the front drive shaft were compromised then the compromised part could fail in such a manner that the crank case (oil pan) would get beaten to crap. In this instance, you have TWO problems, the hubs not unlocking and a compromised drive shaft. If the hubs were failing to unlock BUT the driveshaft was _not_ compromised, the hubs would not pose a problem at all -- the driveshaft woujld simply whirl around as you drive down the highway.
So, bottom line is, you had two problems. The driveshaft was apparently on the fritz and the front hubs failed to unlock. The driveshaft being on the fritz caused the shaft to break and whip all around and take out the oil pan. If that is true, the driveshaft had to wobble and vibrate for a very long time -- I'd suggest weeks, but perhaps only days, at the very least for several hours -- before the catastrophy on the highway occurred. You had problems with this truck that you ignored, the front hubs remaining locked are the least of those problems.
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How would he have known it was locked i 4WD:
If he's just an end user?
RK

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The way he described the damage, it sounded like he was in 4wd. But his story changes w/ every post, first his transfer case grenaded, then it was his driveshaft that let go and beat up his transmission. Finally he tells us the CV joint on the driveshaft was actually what failed, so his damage was not due to the locked hubs, but to a bad driveshaft joint. And he tell us 2 mechanics told him you should not drive with the hubs locked over 45mph, which is a crock...the hubs can be locked as long as you are in 2wd. If you need 4wd, road conditions are too bad for you to go over 45mph anyway. Granted, if the hubs were unlocked it wouldn't have mattered, but he had a bad driveshaft joint as well, and the hublocks didn't cause the problem with the driveshaft joint.

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