How to tell a cast axle to a forged axle

I wonder if the chroming process contributed to the at axle breaking... FWIW CE axles are forged... I'm still amazed at how good Ford's steel was... they pretty much set the standard for their time.

 

I'm betting it was the hit the axle took durring the accident. BTW, I'm still waiting to see a picture of a broken axle (Ford or Aftermarket, Forged or Cast) that didn't take a hit before breaking.

I'm with Desoto. It's Henry or nothing.

 

Are you sure about that? From an engineering standpoint that doesn't compute.
A wishbone would put the LEAST ammount of strain on any axle.
Hairpins the MOST.

 

By looking at the side of the shock..It looks like it got hit 1st. Anyone hear about them that were in the car hope there ok.

 

I think you had better check further into this!!!

 

On the steel...Ford was a leader in all areas of metallurgy, casting, and forging, and used mostly its own recipes for alloys with very few standard SAE steels used.
They controlled the processes from the iron mine to the finished product, and actually did 100% testing on some critical forgings.
Henry himself was an absolute nut on forgings specifically, and used forgings even on ridiculously non-critical things like choke levers and fender brackets on the earliest Model A's...the accountants soon got him to back off a little bit on that kind of application.
I've got the Ford School metallurgy textbook (not a high level text, way beyond me but meant for students who had had chemistry and physics and were moving into casting and forging areas of Ford), which supplied the alloy and heat treat basics for some Ford steels.

 

Yeah, and start by looking at the thin webs around the kingpin on the Ford tube axles. If those were cast, a strong man could probably grab a spindle and snap it right off at the kingpin bosses. If those were not forged, there wouldn't be any of those left at all. Or anyone who drove one...

 

My thought...grind away the surplus weld, and if there are no cracks or voids showing by the time you get down to the meat, it's a good one.
These things were produced on a sort of beta-test experimental production release basis, with small batches in the very low hundreds released from the Rouge plant only so the actual public could pound on a few. I ***ume Ford was looking for a cheaper/lighter axle and wanted a real world durability test.
Will go home and stare at mine some...interesting hypothesis.

The release (mostly on '38-9 85's) is described in the V8 club book on those.

 

I have the ductile/nodular CAST-IRON spec that is generally used for cast spindle/caliper bracket modern spindles at work. I will try to remember to bring it home next Monday and post it here.

Personally, I would only use FORGED spindle ends/batwings whatever and heavy-walled tube mid-sectioned if I was to ever build a rod that could use one!

Just me tho.

pdq67

PS., and there's only three cast-irons regardless of alloys and such in each cl***!

Malleable, some tough like old-fashion hog-ring pliers.

Gray, crack like an old cast-iron skilet, and

Ductile/nodular, darn near tough as nails but will still tear/crack!!

Real cast-steel is a different animal because it doesn't easily spec. reference back to it's rolled/forged steel counterpart. And usually cast-steel is poured using the old "lost-wax" process to make delicate parts like rocker arms and such.

 

My forged axles sound like wind chime when hung up together. Old anvils are this way, if they ring they are good, a dull thunk equals no good.

 

He's correct... you want a four bar with a tube axle UNLESS you have a stock unsplit wishbone or one's that's only split a few inches for driveline clearance.

 

If I'm not mistaken that was from the Day Of the Drags a couple of years ago, and yes he hit the gaurd rail.

Tim

 

Are you sure about that switchover date?? I have a '96 F-150 2 wheel drive and it has the old I beams under it. It was the '97 and newer F-150's that got the A-arm front end...

 

I should have included SPLIT wishboneS

 

I'd say generally cast axles are fine, but they will not bend and flex as well as forged axles will.

Casting flaws are one danger and potentially low level impacts, like hitting the kerb.
High level impacts have shown that cast axles snap but probably the seriousness of the accident will not make much difference to the out come with a snapped axle.

Split bones would have the potential to stress a cast axle more than a forged one, but the comment about hairpins seems curious as hairpins manufactured/designed correctly I always thought were intended to take up some of the flex rather than transfering it to the axle!!!

If you are so concerned about axles breaking then you should also be wearing seat belts.

I'd summarise by saying snapped axles would mostly be the result of an accident, not the cause.

My question is however should we be drilling cast axles???

 

"Split bones would have the potential to stress a cast axle more than a forged one, but the comment about hairpins seems curious as hairpins manufactured/designed correctly I always thought were intended to take up some of the flex rather than transfering it to the axle!!!"

A split wishbone or hairpins have the same function, to hold the axle as rigid as possible.
Hairpins are just a lightweight version. They should not flex..When things flex, it is just a matter of time before they fail..
They work very well on circle track cars but not too well on cars that have to turn both ways. They are even a compromise on circle track cars.
Take a look at a modern sprint car front end..Hairpin on one side and Watts link on the other to keep from binding up..It must work, they get around a 1/4 mile dirt track in 9 seconds.

 

That is one take on it but re-read your comments and you answered my point exactly.
Flat roads dont cause too much of any thing, it is when the suspension needs to go over bigger undulations.

Take a close look at a correctly made hairpin and it has a rotating end and the top and bottom bar are designed to actually twist slightly to compensate for bind, a radius rod battles to do this.
Urethane ends help improve that, but old trackrod ends and limited.

Dont confuse the design of ladder bars with hairpins.

Post a pic of this I'd like to see it.
Take a look at a modern sprint car front end..Hairpin on one side and Watts link on the other to keep from binding up..It must work, they get around a 1/4 mile dirt track in 9 seconds.

 

I dont see the difference between a split bone and a hairpin, the hairpins ive seen have a clevis on the 2 front mount with jam nuts to hold the clevis, Its mounted solid to the axle, basically the same as a split bone. on early ford suspension with split anything, when one side of the axle goes up and down it tries to twist the axle, Its easy to see, take a car with this set up and disconnect the rear attachment to the frame and move the bar up and down, you can easily see the axle twist, not a good condition for a cast axle, 4 bars a different story

 

"Post a pic of this I'd like to see it.
Take a look at a modern sprint car front end..Hairpin on one side and Watts link on the other to keep from binding up..It must work, they get around a 1/4 mile dirt track in 9 seconds."

Do a search for "sprint car suspension" or pics of World of Outlaws sprint cars.
There must be at least 10000 pics on the internet.

As far as the rest of the stuff, I don't make it up, I just relate what is in the ch***is engineering books available at any library.

 

Even a forged axle can break if it has been chrome plated improperly. Hydrogen embrittlement.

 

Pete...Just remember that a sprint car suspension doesn't have to last 100k miles and they don't carry the weight that a street car would have... 1200# and 2500# and more is a lot of difference. Plus a sprint car can carry the l/f wheel up in the air... it's usually the lightest loaded wheel taking stress off of the front end.

P&J's catalog carries a lot of good tech info on the why's and why nots of an I-beam front end.

From R&C Mag... some opinions......

TUBE VS. I-BEAM
While tube and I-beam axles both accomplish the same basic task, each has its own positive and negative traits that need to be taken into consideration. Tube axles look more aerodynamic, are built out of smooth steel tubing (making them easier to chrome or paint), and are extremely rigid. I-beam axles are either cast or forged, so they have a porous surface that can be more difficult to chrome without leaving nickel shadows in the channel that runs down the center of the axle. I-beams are also slightly flexible and can twist as a car goes over uneven terrain. "The only reason to run a tube over an I-beam or visa versa is personal preference," says James. "Since the nostalgia wave has kicked in, the ratio has really increased in favor of the I-beam, so we are actually developing a 5-inch dropped I-beam that will offer the best of both worlds: the drop of a tube with the traditional look everyone wants."

What is interesting to note here is that for many years the only radius rods available were either the split wishbones or a more refined version called hairpins, both of which bolted to a single mounting point on either side of the frame. This worked great with the dropped I-beam axles that were available at the time, because the radius rods allowed the axle to move up and down and the flexibility of the I-beam allowed the axle to twist slightly when necessary to accommodate strange torsion loads going up driveways or over speed bumps. However, when the tube axle became popular, some argued that its rigidity and inability to flex could exert extreme pressures on the single mounting point of the radius rod, which could cause it to tear right out of the frame. As a solution to this problem, Pete & Jake's came up with the four-bar radius rod system, which had two mounting points on the axle and two mounting points on the frame, with aircraft-style rod ends on all four corners, allowing plenty of movement at all angles. The system worked great, and yet to this day many rodders are still mystified as to whether a tube axle can properly function safely with a standard split-wishbone or hairpin setup.

James takes issue with the steadfast rule that four-bar systems must be employed with tube axles, explaining that there isn't a great amount of travel built into the frontend of a hot rod in the first place. "If a car's total front suspension travel is 6 inches, meaning that the wheels can move 3 inches up and 3 inches down, then the most an I-beam axle can twist is 6 inches in both directions," James says. "Now if one wheel is loaded and one wheel is unloaded as a car with a four-bar goes though a driveway diagonally, the radial twist in the four bar during that period is greater than the radial twist in an I-beam axle, because there is more freedom of motion allowed by the four-bar system. If anything was going to break from work hardening or twisting, it would be the four-bar setup since it is built lighter than a heavy-duty tube axle, but that has never been a problem in the many years that the four-bar has been on the market."

According to Chapouris, who helped design the four-bar setup in the first place, one must consider more than just the axle type when choosing a radius rod, as the steering setup comes into play as well.

 

OBJECTION YOUR HONOR, HEARSAY!

A broken axle caused SOLELY by hydrogen embrittlement????? Do you have a photograph that supports your statement? I REALLY want to see an actual photo of a broken axle that has not taken a hit before breaking be it chromed improperly, dropped or cast.

I've searched and searched for actual evidence and have never found it. These axle myths have been going on and on for years. Still I have YET to see an actual photograph of an axle that broke without taking a hit. ...but my Uncle Joe said that his wife's ex-husband's neighbor said it was true. So it must be.

 

Here is a correctly designed hairpin set up, using urethane pivot points.

This allows more movement, as well hairpins allow the to fork to twist say inwards will the bottom fork has the pontential to flex outwards slightly.
Something a radius rod can not do.

Just because it has been a certain for years does not mean it is right, too may half ***ed jobs on hot rods done out there as it is.

 

Ummm - you think bells are not cast??

.

 

Well - since most axles have brakes on them, and applying said brakes while in motion, slows the axle's forward motion, its a pretty good bet that everyone on this forum will brake an axle...many times a day...

.

 

"I have the ductile/nodular CAST-IRON spec that is generally used for cast spindle/caliper bracket modern spindles at work. I will try to remember to bring it home next Monday and post it here."

It's ductile/malleable cast-iron 65-45-18.

pdq67

 

How to tell them apart?
The cast fake ford axle is noticeably heavier and thicker than the real ford axle

 

Good point.
I think they are all cast these days.

Anybody used those Superbell aluminum axles???

 

I never said it would break SOLELY from hydrogen embrittlement. Here is a quote from a website regarding aircraft maintence.

Hydrogen embrittlement causes high-strength carbon and alloy steel to break well below its rated strength. The part may break immediately, or years later without warning. The aircraft mechanic may accidentally cause hydrogen embrittlement during aircraft maintenance. How you can avoid costly mistakes and blame:
Hydrogen embrittlement may be caused by having parts electro-plated, or parts that have corroded. An example of how electro-plating can lead to hydrogen embrittlement failure is when the mechanic has a worn aircraft crankshaft journal chrome plated back to standard size. There is a long history in aviation of aircraft crankshafts breaking.