Rear Axle Break

[12Ounce]

I see some folks use the center of the rear axle as a jacking point to lift the vehicle. That could also lead to early failure. Of course, heavy debris in the roadway can take its toll.

There are many ways to make the rear axle fail, but normally it should last "forever".

[serge_saati]

I don't think that gridman have used the rear axle to support his vehicle. Of course its a stupid idea.

Originally Posted by 12Ounce

There are many ways to make the rear axle fail, but normally it should last "forever".

I don't think you can said that unless you have designed the rear suspension of your car. It's not because yours never fail that it can't fail, even if it's used correctly.

[12Ounce]

I didn't mean to suggest someone had been careless. I agree, with you, that lifting the vehicle by the center of the axle is "stupid", but I have observed it being done more than once ... So some folks obviously haven't realized the impact of such action. I was hoping to warn/remind us all not to lift by the axle.

In normal driving the middle of the rear axle is not loaded very much. If corrosion and mechanical damage does not occur ... it should last "forever".

A good item for all of us to add to our check list ... perhaps every time the tires are rotated. I know I have run over lots of debris that has bumped along underneath, my axle could well be damaged.

[serge_saati]

An under inflated rear tire can also cause the rear axle to fail. Excessive speed in tight corner too.

Like you said, when rear suspension is balanced from left to right, there's no weight on the axle. The weight are supported by the suspensions. But when one of the rear tire hits a bump on the road, the axle lift the other side of the vehicle a little bit.

In a road with a lot of oddity, there's a lot of stress for the axle. In Atlanta you may have very nice roads. It's not necessary the case in other places.

[12Ounce]

Incoming! Incoming!

Man, driving thru that ain't "normal"! Baghdad? (LOL)

[serge_saati]

Originally Posted by 12Ounce

Incoming! Incoming!

Man, driving thru that ain't "normal"! Baghdad? (LOL)

No, it's North America. And you didn't see all!
Sometime I need to switch lane to avoid braking my shocks, cause there's a very big pothole in main street. When it has traffic, I didn't have the choice.

[12Ounce]

Atlanta has sinkholes ... swallows up entire car and occupants in an instant. And parking decks that fall.

[gridman]

Hi Again, (warning, this is going to be a long one!)

I will try to answer your comments in the order received.

serge_saati wrote;
quote,
“When it happens, did the tracking bar was in good shape? Tracking bar helps axle beam to not twist too much.

Maybe too much fuel in the tank doesn't help the beam too live longtime. I never fill more than 3/8. Also, I consume less fuel (less weight).”


Good Question.
All arms/bars were in good condition, and bushings were not worn or loose.
While the axle was out and laying on the driveway, I took the opportunity to replace the rear shocks and clean and check the rear brakes, not because there was a problem with them, but because at 72,000 miles (for the shocks) it was a convenient time to do it before they needed it.

I seldom have the 25 gallon tank more than ¾ full, and this Ford rates as a 7 passenger minivan that I seldom carry more than my family of 4 in (2 of which are preteens). Far less weight than Ford rates this vehicle for!

12Ounce wrote;
quote,
“I see some folks use the center of the rear axle as a jacking point to lift the vehicle. That could also lead to early failure. Of course, heavy debris in the roadway can take its toll.”


No, I do not raise the vehicle by the axle tube. From what I have read on other websites, this has been the excuse some dealers have given to their customers to explain the break. My favorite was a dealer showing the customer the dimple on the bottom of the broken axle as proof of where the jack was used to raise the vehicle. This excuse satisfied the customer until he brought the vehicle to his mechanic. His mechanics put it up on the lift, and when they checked the brand new, dealer installed axle, guess what they found? That same dimple!
It seems that dimple is from the forming process in making the axle tube.

To raise the vehicle from the center of the rear axle would put the stress on the top of the axle tube.
These axles are cracking, starting at the bottom, the area most stressed while driving.

12Ounce wrote;
quote,
“In normal driving the middle of the rear axle is not loaded very much. If corrosion and mechanical damage does not occur ... it should last "forever".

A good item for all of us to add to our check list ... perhaps every time the tires are rotated. I know I have run over lots of debris that has bumped along underneath, my axle could well be damaged.”

And,

serge_saati wrote;
quote,
“Like you said, when rear suspension is balanced from left to right, there's no weight on the axle. The weight are supported by the suspensions. But when one of the rear tire hits a bump on the road, the axle lift the other side of the vehicle a little bit.”



The axle IS part of the rear suspension!
If the rear springs (that carry the weight of the back of the vehicle) were directly over the center of the tire/wheel/hub, then yes the axle would not carry much load. But as that is almost impossible to engineer into a passenger vehicle, the load is carried inboard of the tire/wheel/hub, on the axle tube. The axle then transfers the load to the outboard hub/wheel/ tire. This off-center loading tries to twist the top of the wheel in (negative camber) on both sides of the vehicle, which is resisted by the axle tube between them. The axle is resisting being twisted down in the center putting most of the stress on the bottom of the axle tube. The area where the cracks are starting!

As I said in my original comment,

The problem appears to be part design;
A straight tube with large openings (bottom spring seats) on each end that lets water/road salt get in and not easily drain out.
And part material or process;
Poor quality steel or missing an internal coating to resist corrosion.

[serge_saati]

Originally Posted by gridman

My favorite was a dealer showing the customer the dimple on the bottom of the broken axle as proof of where the jack was used to raise the vehicle. This excuse satisfied the customer until he brought the vehicle to his mechanic. His mechanics put it up on the lift, and when they checked the brand new, dealer installed axle, guess what they found? That same dimple!
It seems that dimple is from the forming process in making the axle tube.

Dealers know all the tricks to crook.

[12Ounce]

OK, I'm now getting a case of paranoia! My '99 has 270 kmiles. Original rear shocks. We are planning our second round-the-country vacation trip next summer ... ten thousand plus miles ... I do not need anything coming apart, including a rear axle beam. So, I'm thinking ... best to go to dealer and get one of these things ... paint it up good with rust inhibiter, install it just to be "on safe side". That was before I saw the price ... $375 before taxes!

Does anyone have an image showing the fracture? Is it wise to weld on some extra reinforcements?

Just for info: The local dealership has only sold one (... at that price, I can understand why ...) back in 2007. The part # is 4B435. (Models 1998 - 2003). No related TSB's. One part number change ... may have been a new supplier instead of an upgrade.

[serge_saati]

Like I said, on highway the axle beam is almost not under stress, whenever how much miles you do.

It's under stress only on streets filled of potholes (like mines), on off-road trail, or when you turn a tight turn very fast.

The long as you turn 90° curve below 10 mph you should be ok. Some peoples do it at 20 mph and more.

Check also tire pressure and rear shock absorber. Weak shock can cause axe damage.

For the rust inhibitor, you can do it yourself. Just spray 5W30 oil under the car with a sprayer.

[gridman]

And like I said, the axle tube is always under stress whenever there is weight on the rear tires, it’s basic engineering (or middle school science). To lessen the stress, you could try to drive straight on the world’s longest billiards table (as Serge’s suggestion seems to imply), but in the “real” world I doubt you will find any roads that smooth or straight.

As for slowing to 10mph for 90° curves, this would present a new safety issue, as a line of 18 wheelers drives thru your tailgate on the highway!

As for spraying 5W30 oil under the car with a sprayer, this will keep the bottom of your vehicle “nice and shinny” and may keep the exposed surfaces free of corrosion for the short term, (for the first 2 or 3 substantial rain/snow storms) but will soon wash/wear off. But as I said, the axle rots from the inside out, so any spraying on the outside of the axle will not address the problem growing on the inside of the axle.


The best way to attack the problem directly, would be to raise the rear of the vehicle, remove one (or both) rear wheels to get easy access to the “drain holes” (small rectangular holes at the bottom of the tube, inboard of the springs) and spray/fill the tube (both side of the U shape) with a rust converter/corrosion inhibiter. Please Note, It would be a good idea to first check the inside of the axle with a bore scope (if available) to see the extent of corrosion already present. If there is already a lot of rust build-up/scale it may be too late for a coating to be much help!

To address 12Ounce’s concerns;
As I said, the problem appears to be part design (I believe all Windstars share the same axle design), and part materials/process. There is a very good chance that not all Windstars shared in the same material/process problems. This is something only Ford would know (but is not revealing). While all Windstars were built (assembled) in Oakville, Ontario, Canada, their parts were, most likely, sourced from all over the world. These axles may have been manufactured in a plant in the US or Canada or Mexico or China or anywhere else in the world. There is also a chance they were supplied from more than one plant or company and from more than one country and different manufacturiers in different years. The only thing they had in common was they were all made to Ford’s design specs. and they were the lowest cost manufactures of the part. Add to this that these manufactures would be using steel sourced from anywhere in the world, as long as it was the lowest price, and they probabily also received the steel from more than one supplier. This means your axle could have been made in made in Texas from “virgin” steel from Pittsburgh or made in Mexico from recycled scrap metal from China, only Ford might (should) have a record of this. Additionally, was the “raw steel” axle coated with corrision resistant paint, inside & out, by spraying or dipping? Or was it only sprayed on the outside after being built?
If it was to be sprayed on the inside, was the spray equipment beoken that shift/day/week? And when did anybody notice.
Also being from Atlanta, I assume your vehicles are not exposed to the same road salt we are up here and there is no large body of salt water, so I’m sure that helps. I also wonder if that red clay dust that coats everything down there might be helping your vehicle.
As for the dealer price of $375 before taxes for a new axle, your lucky, up here it’s above $500 and they want another $500 to install it!
I have read of someone getting it welded (successfully), but you need to bring it to a good welder who knows what he is doing, and you need to bring it to him before it cracks thru (or when the crack first appears but befor the axle starts to bend), also after it is welded it is a very good idea to get the vehicles complete alignment checked, front & rear.

[12Ounce]

Thanks all for the info.

Duh, I'm just now noticing gridman's "avatar" .. that's the cracked axle-beam, right? ... anyway to increase the size of that photo?.. I printed it and got a postage-stamp.

[gridman]

Yes that is a picture of my broken axle.

Except for the "avatar" photo, I have not yet figured out how to post my photos onto this website (apparently they are too large to be an attachment).

If you want to see some of my photos of my broken axle, (along with other peoples photos of their broken Windstar axles, go to http://www.carcomplaints.com/Ford/Windstar/2001/drivetrain/rear_axle_snapped_in_two.shtml

[serge_saati]

Originally Posted by gridman

I have not yet figured out how to post my photos onto this website (apparently they are too large to be an attachment).

No they're not too big. But there was a problem on this website with attachment since august 2009. So you can't upload picture directly from you PC.

But you can upload pics on your web server or on ImageShack.us site.

Then insert image url on the post.