Featured Technical Super Bell axle

As hot rodder's we all do "stuff" that's not exactly safe, no front brakes, "fruit jar" master cylinders, no windshield wipers, ETC. An "I" beam axle consists of two flanges and a web. In construction, both steel and LVL wood beams require structural and mathematical formulas to get the right size. In steel I beam construction, drilling or cutting holes in the web is never allowed, legally that is. In wood LVL beams drilling is allowed by following strict formulas as to the size of the beam and hole size. I have seen I beam axles that have holes drilled in them that are too small and it does not look right, so the answer is drill bigger holes. I have seen holes drilled in axles that actually touch the flanges and that vastly changes the structure of the beam. The mathematical formulas are very complex, but I wonder if anyone has ever taken the time to see how drilling different sized holes effect the I beam axle structurally.

 

I have some guys that I work with that could make quick and easy ****ysis of what putting holes in these I beam axles actually does to strength. However, modeling one up to do that would be the first step as well as knowing the actual loads on the axle. Anyway, if someone had an axle modeled up for something like a 32, I would volunteer that we could do the ****ysis and report back. The closest I have done to modeling up an axle so far is when I modeled up a sign for Sid to hold one...

 

I have had several Ch***is Engeneering Forged axle. HRP

 

@ocool25


Hello,

I moved the photo around so the two ends meet or sort of meet. But, I am puzzled as to the goopy stuff on the end of the axle going across. (blue arrows)

But, besides the point, the weakest point of a drilled axle are the holes. The holes nearest the ends seem to get more action and therefore could happen again. It does show the crack right in the hole area...

Yes, thousands of hot rod folks have drilled axles. We had a solid one on our 327 powered 1940 Ford Sedan Delivery. It never cracked over the 1000s of miles we drove all over the West coast and inland portions of California.


Jnaki

At least the axle company stood by their product... good on them.

 

I have slightly less concern about axles that have broken during a crash then I do when axles break before a crash, because those that break before the crash are often the reason for the crash.
Axles are not suppose to break at all, as far as I'm concerned, but I have seen some mangled stuff after crashes.

Back when beam axles were the thing to have on dirt tracks, it was not unusual for the left front tire to be off the ground coming through the turns, when the cars crashed. I've seen beam axles really bent up, and I've see them ripped out from under the cars, but I don't ever remember seeing an axle broken.

 

How an axle is impacted will have great influence on whether it breaks or not. The normal impact is mostly vertically with only a small portion of the load being horizontally. So when your car is traveling down the road hitting bumps most of the impact force is vertical. With this car being struck directly to one front tire by another car all the force was horizontal against the tire and the end of the axle was pushed backwards while the spring held the axle at the perch. Not the usual impact an axle ever sees, thus it stressed it in a direction that caused it to break. Might have been 1 mph, but how much lateral force the heavier car's impact caused would take an engineer to figure out.

 

What a coincidence, so do I!

 

The holes in the OP's axle look like they are drilled high in the web and could be affecting the top flange.
@ocool25 , did you buy the axle drilled or was it drilled after it was purchased?

 

With an axle with that much drop, when the tire hits a solid object it also causes the axle to twist, due to the lever action of the spindle being 6 to more inches above the axle beam.

 

Would probably be fairly easy to figure out the forces involved if you knew the slope, weight of both cars, distance traveled to impact, and distance both cars traveled after impact, and some measurements from impact point to vehicle centrelines. Probably, a few ***umptions needed as well.
Judging by the fact that it fractured where the hole was, it makes sense due to the reduction in cross-sectional area. The fact that the hole centrelines are a little biased upwards I don’t think would have made much difference in this failure mode (horizontal bending moment - I think).

 

With the drop, the holes and the added scrub, lots of stress on that axle when the tire was impacted head on. Even if it were a forged axle, it most likely would have bent.

 

Is it possible that axle had stress/pressure with Caster more or less then the front cross member had in the position , as in lets say few deg's of rake
The spacer 0 , the cross member what's stock on 32 4 deg's ? Any ways U bolts
Clamping axle in one Direction
Then 4 bar / hair pins pulling or pushing in opposite direction Axle not relaxed & having stress & or twist bind contribute to breakage ?

 

Try to imagine a beam (axle - blue) supported at two points (hairpins - orange). Impact occurred on tire (yellow). The resulting force pushing down (***ume top view), creates a resulting force pushing up on the axle/beam and a moment that wants to bend/twist it CCW. It breaks at its weakest point (pink circle representing the hole in the axle).
NOTE: pink hole is rotated 90 degrees just for visual aid. It is supposed to be a top view of the axle.

 

What's next, diagram this with an interpretive dance?

 

Be careful what you ask for…

 

Aluminum with holes doesn't get it buy an old steel axle and Paint it

 

I have one of the newer P&J's forged axles in stock. I was gonna replace the cast axle under my daily driver deuce pickup but never got to it. I've also used quite a few of the forged Roadster Supply front axles.. Made offshore but very good quality.

 

none of the above is allowed here, probably not in Australia either.
perhaps it is time for some hot rodders to step into the 21st century regarding safety issues !

 

@clem just asking & curious
Over there what chain of autopart's store's do you have there ?
Here two big chains's AutoZone
Avance Auto , on shelf there are several things being sold to unsuspected buyers that do not know better that are unsafe and junk.
none name brand on shelf
Lug nut
Wheel studs
Bolts even so called G 8 all above
Cheap & wrong thread pitch.
Brake line fittings incorrect wrong inverted taper ,
Cheap br*** both thread & inverted shape .
Cheep rubber hose , house clamps
Exhaust clamp's tube , pipe several gauge thin
Tires cheep junk , not sold by neither
Store's ,
List is long
& NAPA has went down hill selling more & more cheep junk

 

You can not compare the steel used in the twisted axles in posts #46 and #48 to todays aftermarket axles. Ford used what was known as "Vanadium Steel" that was reportedly 10 times stronger than the steel made by U.S. Steel. Who knows what the **** we are getting from China is? I have never seen a real unmolested Ford axle fail.

 

That sure seems to be the case around here. I been a NAPA guy for 60 some years, gonna have to branch out I guess.

 

All the more reason to put the effort in to find an original Ford axle and have it properly dropped.
If that can't be done, at least put the effort in to shop wisely for a good quality aftermarket forged one.

 

I was told at the time of my purchase of a Super Bell axle that some were coming out of Mexico. Maybe not as good quality, im not sure. Hence why I had to get mine tested. Mine was either the first or second axle to get done down here. Here is the fancy certificate to gets issued, for anyone interested. Cheers

 

Repco - 128 stores nationwide - Australian owned by ; Genuine Parts Company - according to Wikipedia
Supercheap Auto - 41 stores nationwide according to AI. - I believe also Australian owned by ; Super Retail Group
are the only ones in smaller provincial towns.
I think NAPA is in some of the cities now, but not huge. - 22 stores nationwide - I ***ume it is the same as your NAPA

on a side note; (sorry, a bit off topic for axles)
I was looking for brake parts the other night that are difficult to find here, but found some online
manufacturered by AHRP, which means - American Hot Rod Products
I am ***uming a Chinese product, ( due to pricing ), and wondering if they are over in the USA - as I can’t find any reviews online.
Decided not to use them anyway.

for my daily driver needs and batteries and general items, I deal with my local car dealer, even though none of my vehicles are their brand.
40 years dealing with the same business, they seem happy to put up with me.
Small town people……….

 

@deadbeat how long ago did you have that done ? And the most important question, is that good ?

...

 

@lostone it was done in 2013. As far as good, I guess, piece of mind, cheers

 

Forged is the safest answer , forgings will break . I sent an LT1 crank out to be reconditioned . When I went to pick it up he handed me 2 pieces . Said it was .002 out of being straight and it snapped .

 

Is this legal reasons?

 

@leon bee I'm pretty sure that's for registration / legality on the road purposes, as opposed to say liability type legal issues.

NZ and Aus have it pretty tough in the regulation department.

Chris