Ford Auto Hubs can cause spectacular failure

Page 3 of 3  


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.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Yours is quite a different system... It uses FWD style CV joints at the knuckles and the front diff - double offset at the knuckle and tripot at the diff (the reason is the tripots can "plunge" while double offsets cannot).
Add that the intended use of the SuperDuty and your cars is very different as well....
As long as the CV boots are inspected regularly for deterioration or perforation, you should get many happy miles from your cars....
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Thanks. I'll keep an eye on the CV boots. And -- I assume if I find one ripped or about to rip I pull the CV joint, clean it, re-grease it, and put on a new boot -- just like on my old swing-axle VW Beetles.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I don't really understand the sequence of events here. Where exactly was this joint that failed? If you were driving with one hub locked in, or two, forever, why would any universal joint fail? I don't see the connection. Does anybody see it?
I have to assume that when you said crank case you really meant the transfer case. It's not easy to break that piece except maybe through failure of the frontmost u-joint. The joints inside the axle wouldn't explode anything if they broke. At least I don't see how.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

He pulled his pontoon boat out of where it was parked / docked in 4x4 , then didn't take it out of 4x4 and flew down the highway. the t-case exploded and took a cv joint too.
now he wants ford to pay
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
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
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
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.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Let me clarify something here, Rob. Think hard about this.
When modern-style 4 wheel drive vehicles first came out, they didn't have locking hubs. Jeeps didn't have that in WWII. Pickup trucks didn't have it in late 50's, the 60's and some of the 70's. Do you know what they had? Just a solid connection. You were expected to drive the vehicle 100,000 miles, or whatever it took to wear it out, with the hubs locked in and the front drivetrain rotating the whole way.
Do you know what this damaged? Nothing. Just like the rear drivetrain rotating doesn't hurt anything. So whatever your situation was, the hubs have nothing to do with it.
It is true that when a u-joint breaks, you can drop one end of a driveshaft on the road. If you do that, the driveshaft's rotation will probably hit something and that'll break all kinds of stuff. Wouldn't be unusual. With the front driveshaft, you have the option of stabbing it into the road and doing a bunch of damage that way.
So basically you claim the root cause is a universal joint failure. It's still not clear where the joint is, but I'm going to guess you mean it was a double universal joint and is part of the front driveshaft.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I think I agree with some other posters who suggested that you were in 4WD. That makes a lot more sense than your explanation. I don't think the hubs were at fault.
The problem with your explanation is that you made it up. After your tranfer case broke open, you surveyed this pile of parts and then made up a series of events to explain it. Right? You need to think about this. If you know what failed first, you should certainly say so, but I so no reason to assume that you actually know what the root failure is.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I didn't make anything up ... the transmission shop told me what happened. Now, that's not to say they couldn't be wrong about it, but when I first called and explained the vehicle and the failure, and asked what might have caused it, the mechanic told me they've seen many similar failures, and the hubs have always been stuck in locked position.
Anyway, I don't really care *what* caused it, I still don't think parts flying all over a highway is an acceptable failure. Neither did the NTSB investigator (who referred my to NHTSA, since NTSB doesn't deal with auto issues).
Y'all are free to believe I was in 4WD, but as I stated earlier, there's a distinct difference between the binding in turns I felt when NOT in 4wd and the binding when I had it in 4WD. Yes, I've occasionally forgot to take it out after pulling my boat, but the first turn I make it's *very* obvious. I made several leaving campground, as well as countless turns in the 100 miles before my son took over driving. He didn't touch it, and it wasn't in 4WD after the incident.
Could there have been another failure that caused it to go into 4WD by itself? I suppose so, but my guess is that problem would still exist.
Rob

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

As far as I know, the vacuum is used to engage the hubs, the hubs are spring loaded to unlock. In any case, by your description, you hubs have been locked for a very long time. The failure mode is more often that the hubs do not lock when asked, your experience is opposite that of most people with problems in this area.
The result of your problem, exploding transfer case, is what I would expect though. (Your transfer case exploded, by the way, not the crank case.) Having said that, having the front hubs locked in 2WD would not harm the transfer case, transmission, or crank case.Lots of 4WD systems don't even have hub locks anymore, the front hubs are always locked and the 4WD system is engaged and disengaged solely by the selection of the transfer case. If the transfer case is not selected, the front tires merely turn the front drive shaft, but the front drive shaft is not connected to anything inside the t-case, therefore no damage is done. If your truck was being operated unknowingly in 4WD on pavement, then the tcase would explode. But, having the front hubs locked would not be an issue if the truck was really set to 2WD. (I've been operating my Jeep with the front hubs locked, and the tcase set to 2WD, for going on ten years, and there is no damage or ill effect of any kind.)
Your complaint that there has been noticable binding in turns (I assume parking lot manuvers and the like) is a sign that your truck was in 4WD. The front and rear tires on your truck will travel different lines when making a turn in a parking lot (they travel different lines in any turn, but you will feel this in a parking lot more than on the road), and the binding you feel is the front tires scrubbing on the ground to release the stresses of the turn.
The differentials accomodate the different arcs that the left and right tires travel in any turn, but the transfer case has no capacity to accomodate the different tracks of the front and rear tires. The result is that the transfer case gets stressed severely when the truck makes a tight turn on pavement. If the same turn was made on dirt or gravel, the front tires would slip on the ground and release the stresses, and you would not feel the binding that you felt on the pavement.
Your truck is equipped with Part Time 4WD, this means it is intended to be used part time only, it should not ever be used where there is sufficient traction (dry pavement) to hold the tires from slipping on the ground. You ought not even drive you truck in 4WD in the rain, and unless snow and/or ice is covering the roadway where you are driving, you should not use 4WD at all when driving on the street.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

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.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

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.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Me thinks that is a BS story full of holes. For one, even if you did not back up properly to disengage the autophubs, the only result would be the axles and front shaft would be turning and at the same speed as if they were engaged and being driven.
mike

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I still think he had just pulled the pontoon boat out of the water and had 4wd engaged from the loading ramp. Maybe he flipped the switch on the dash to 2wd, but the mechanical tension alone on the transfer case from the automatic transmission could have kept it engaged.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.