Ford Auto Hubs can cause spectacular failure

Because the operator is a maroon (sic), or the 4WD system is broken. My vote is the former ...

Reply to
Jeff Strickland
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Actually, if the automatic hubs are working properly they are supposed to unlock as soon as you take it out of 4wd. That's the whole point of auto hubs. The problem is (as I found out) they don't always work right. That's why I now have manual hubs -- cheaper, and won't have the same problem again.

Rob

Reply to
Rob

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

Reply to
Rob

Yes, but the transfer case disengages as well, so even if the hublocks are engaged, you still won't be in 4wd if the T case is in 2wd.

Reply to
Matt Macchiarolo

Thanks for the info, Jim.

I've hit every regular maintenance point with the vehicle, so if maintenance was missed then Ford dropped the ball. Not an impossibility.

There was a vibration, but only a few seconds before things fell apart. The vibration was followed by a whine ("oops", foot of gas, looking to get off road), followed by the chaos of everything going to pieces.

The truck had 51k, and front hubs were replaced about 43k. Spindle should have been taken care of at the same time.

Who knows what else might have been going on in the transmission, crank-case, etc. that could have contributed. The CV joint had obviously blown, which was the start of the chain reaction.

Rob

Reply to
Rob

The act of shifting in and out of 4wd definitely was engaging/disengaging the front transfer case. Every time I've spun back wheels on a slick boat ramp, shifting to 4wd pulls it right out. There's also 4wd roads I would have been able to drive in 2wd. Yet with the hubs set to "automatic", they still were binding in turns (although not as much as the few times I made turns in 4wd).

This is kind of what led me to believe a little binding in hard turns was normal. I could definitely see the difference between dialing 4wd and 2wd, and not really understanding at the time the way the hubs worked ...

Rob

Reply to
Rob

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.

Reply to
Matt Macchiarolo

"Hubs" were replaced at 43K, or "hublocks"? That is a different from the bearing assembly, which in the SD is a unit assembly, as opposed to a standard spindle-bearing setup.

How do you know that's where it started? If the CV shaft blew, it would disconnect from the transfer case, and bang around a bit. Explosion of the T case would easily destroy the CV joint in the front driveshaft.

Reply to
Matt Macchiarolo

After re-reading your OP, you are calling the joint on the axle a CV joint. It is a U-joint. The joint on the transfer case end of the front driveshaft is a CV joint.

Reply to
Matt Macchiarolo

Just to make it clear, the CV joint that failed is on the front drive axle, between two U-joints. There's supposed to be something like a little ball inside the CV joint, which was gone (only a little piece left).

This resulted in severe vibration in the crank-case (attached to the front of the transmission), which caused it to fly apart. This resulted in the automatic transmission being destroyed. Apparently this all happened within a few minutes, as about 20 miles earlier when I was driving the pickup there was no vibration, nothing abnormal. My son was actually driving when everything fell apart.

It was not in 4wd, as that causes REALLY bad binding when turning on dry pavement, and both my son and I are totally aware of what that feels like. The binding I've noticed all these years, when in 2wd, is very slight, and only when cranked all the way left or right. With the Warn manual hubs, as well as when the last set of auto hubs was brand new, there's absolutely no binding in a hard turn. I don't really recall if it did that brand new, but I don't think it did.

Maybe mine experience is unusual. Certainly spewing pieces all over the highway is. It still wouldn't hurt for anyone with auto hubs to make a couple of hard turns in 2wd and make sure they're not binding. If they are, then it should be checked, no?

Rob

Reply to
Rob

"Front transfer case?" How many transfer cases does your truck have?

I think you mean "front axle." The transfer case is what engages the front axle.

I think I found the problem.

Reply to
Matt Macchiarolo

So it wasn't the fault of the hubs being locked, it was the CV joint in the front driveshaft that failed. Your experience is unusual.

Reply to
Matt Macchiarolo

So it would appear.

It's possible I got that wrong. I thought the crank-case was bolted onto the transmission, at the back end of the front axle, with the transfer case at the front end of the axle (I'm an expert on a few things, but not autos :-). What exploaded was what I thought was the crank-case (at the back of the front axle).

This is contrary to what the Ford mechanic told me. He said driving over 45mph with hubs locked, either set to lock or due to failure, would cause stress on the drive train, at least on my 2000 pickup. It's possible he's wrong, though.

Many replies I've read have said I must have been in 4wd, but I have no doubt it was set to 2wd. I'm pretty near certain that part wasn't broke, as the binding that occurs in 4wd is much more severe than what I'd noticed with hubs locked.

Reply to
Rob

Not so. The crankcase is where the oil lives when the truck is parked, and where it pools while the engine is running, waiting to get sucked up by the oil pump to begin its journey through the motor once again. There is no immediate relation between the crank case and the parts that exploded.

Both the front and rear axles are connected to the transfer case via the respective drive shafts.

I have to think you've gotten some terms confused. The t-case can only explode if it is engaged on the highway. Period. The front axle can be locked while the tcase in in 2WD, and no damage will result.

You _think_ it was set there, and there is a chance that you set it there, but in actuality, it was operating in 4WD when it blew. The front axle will not blow a transfer case set to operate in 2HI. I do not know how confusing the system may or may not be, my '95 Bronco had a similar system. You are suggesting that you selected 2HI, and if so, the transfer case did not respond to your selection. This does not change very much, you still have a t-case spread across central Colorado, but it narrows the problem set a bit.

I am not prepared to engage in what you did right or wrong, but all that I know about 4WD systems, front hubs being locked in and of themselves can not cause the transfer case troubles you have reported. Your particular problem set can only come about if the transfer case was physically set to 4WD while on the highway, and this had to be the case for a very long time.

My Jeep ('81 CJ5) has Detroit lockers on both the front and rear axles. I once (when I first bought it) pulled out of the dirt and onto the highway without selecting 2HI. With the variance is tire diameters on all 4 corners, as I approached 45ish MPH, my Jeep started to swerve all over the road. The cause of this was that the front and rear and the left and right were all going different speeds, and the traction on the roadway was fed back through the tires to the steering wheel.

Your tcase did not explode because the front hubs were locked, it exploded because it was operating in 4WD. If you intended it to be in 4WD, you made a serious mistake. If you thought it was actually in 2WD, then your truck lied to you for a very long time.

Reply to
Jeff Strickland

The trouble that auto hubs have is that they do not LOCK properly. The vacuum system that engages the hubs will fail, and the hubs will consequently refuse to engage. If the vacuum is lost, the hubs unlock and

4WD is disabled.

When the 4WD system fails to unlock, it is physically bound up and can not unlock. If this is the case, you must stop and go in Reverse a few feet to allow the stress of the previous 4WD operation to be released.

If you were engaged in 4WD operation, then pressed the button ot return to

2WD, but did not provide the environment for the system to release, then you could easily get on the highway and drive for hours in 4WD, thinking all the while that you are in 2WD.

You will like the manual hubs. Set them at the trail head, then shift into and out of 4WD as you need. If the weather sucks, then you can leave them locked, and avoid getting out in the snow or rain to unlock the front end. My front hubs have been locked for going on 10 years ...

Reply to
Jeff Strickland

And be sure the transfer case shifts out of 4wd. Even sometimes the indicator will show it but tension on the drivetrain will keep it in 4wd. You can back up to be sure, but usually shifting the transmission into neutral will relieve the bind and allow the T case to disengage.

Reply to
Matt Macchiarolo

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.

Reply to
Kickin' Ass and Takin' Names

I have a 2004 Explorer with automatic 4WD and selector buttons on the dash for 4WD HI and 4WD LO; Also have a 97 Mazda B4000, 5-speed with dash mounted selector switch -- 2WD, 4WD HI, 4WD LO.

Do I need to lubricate the front hubs as part of a normal service??

I do not run either of these vehicles off the road. Every six weeks or so I do take each of them out onto a rough local road with loose gravel and a steep up-grade, shift into 4WD HI and LO which I think is supposed to keep the hubs lubricated. During hunting season the Mazda takes a lot of trips on bad roads where I use 4WD HI and LO as needed.

Thanks.

Reply to
Kickin' Ass and Takin' Names

messagenews: snipped-for-privacy@50g2000hsm.googlegroups.com...

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.

Reply to
Kickin' Ass and Takin' Names

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 d>> Explorer does not use the autolock hubs on the Super Duty.

Reply to
Matt Macchiarolo

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