Hot Rods Please post detailed pictures of "Failed, 35-36 rear Wishbones"

Here's an example of improperly installed 35/36 bones; yeah, welded directly to the front of the axle. And if that wasn't horrific enough, the bones were mounted to the perimeter of the frame, with rigid ends....no heim, no rod end! unreal! Bent like a field hockey stick. Mild 283 for power, but 10-inch wide cheater slicks for rear stiction.

 

Alright,... I don't want to be disagreeable,... but if you look at the picture of the 35/36 bones,.. you will see the weld is very close to the first upright boss and the formation of the "I" beam portion.

When you look at the one you posted, there is a greater distance between the factory weld and the "booger weld" to the axle.... like a 1937 and up.

One more thing, the distance between the factory weld and the front of the wishbone bung, looks really short, The 35/36 bones are really long between those two factory welds.... I would guess these were actually 1941-1948 Bones,.... the thin wall ones. I would expect this to fail.

Note: It looks like they tried to use the 41-48 factory Ford spring hanger welded to the later model rear axle,..... Another really bad idea,..... And I am really surprised that didn't fail as well,... If they were actually 1935/36 rear bones with the spring hanger attached to the wishbone,... they wouldn't have to go through all this extra monkey motion... They could have found another way to screw things up.

 

This is the problem.

The wish bones have been cut off of their original forged pieces, and a 3/8" plate has been welded to them.

The crack happened right where the 3/8" plate ended.

Plus, they were split.

That only works if the rear end moves up and down.

But if the rear end articulates... one wheel up, one wheel down...

it puts a twisting force on the bones.

I am going to glue up some popsickle sticks and do an example.

Sam

 

I've been watching this with great interest, having had no previous experience with this setup. I was concerned that I may have to run a torque arm setup on my '36 3-window, but having followed this thread, combined with the fact I'll be running 7.00-16 rears (the weakest link), I now feel pretty sure that my setup will be fine.

My main issue is that the rear bones are already above frame level (the things we do to get 'the look'), and adding a torque arm was gonna' encroach even further into the floor area.



I made up this 'truss' type mount for the front end of the bones 'cos the x-member has been spread apart for transmission clearance. (Still to be final welded)



I had been worried about the bones 'wrapping up' under load, but you've all put my mind to rest.



Happy now!

 

Very nice !

 

I have the same setup as described above - joined with the pivot of a front wishbone.

I intend to run top arms just like the Rolling Bones in this example.

 

Just a point of interest,... Again these are NOT 1935/36 Rear Wishbones,... these are the thinner 1937 and up wishbones.

 

Surf City...

The problem I see with your set up is that bones are split.

And with a rod end like you have it... you might experience a loosening of the jamb nuts.

I would keep an eye on them.

You could very easily connect them and then use a large heim joint for one mounting point.

It might very well be ok, though.

Sam

 

Ok... a few popsicle sticks glued together and you can see the bones twist.

Don't hang on every word... I just started talking... so the bit about "use any wishbone" isn't what I meant!

Aanyway...

Here you go!

<iframe width="420" height="315" src="http://www.youtube.com/embed/okBrx2RTUAQ" frameborder="0" allowfullscreen></iframe>

Sam

 

I posted the picture to illustrate the re-inforcing, not the 37-48 type bones. I have 4 sets of 36 bones, some I havr bought here.

 

Cool little Video, very informational, and I agree something like spherical rod ends might help reduce the stress on the bones.
Not to pick the fly **** out of the pepper, but what you/we are calling wishbones are not wishbones. They were just "support" rods/ spring mounts for the torque tube which was a single pivot, and provided no real torsional support other than to strengthen to torque tube which they were mounted directly to, not the frame. the torque tube did all the twisting, shifting, etc...
In my opinion though the 36 rear "bones" are plenty beffy enough to run in a "ladder bar" type application and I wall gladly do it again and again for as long as I'm working on Hot Rods.

Drew

 

Thanks for your concerns.

I will definitely keep an eye on the jamb nuts for any loosening, although I don't see that there will be any more twisting at the rod ends than there would be with a four bar setup (I realise that in a 4-bar there are two urethane ends 'sharing' the twist, but the 'almost' triangulation of my setup should minimise the effect).

Certainly if it had been very easy to connect them for one mounting point I would have done so, but in this instance, that theoretical point would be right in the centre axis of my driveshaft!

 

That's why I said "Don't hang on every word"...

 

Not directed particularly at you. Except maybe the part about it being a very informative video. Somthing is always lost in a conversation on the internet I guess.

 

That's true about a four bar twisting...

And a '36 wishbone can definately afford to twist more than a little short four bar bar...

Sam

 

True!

Hug?

Sam

 

I thought i would bring this thread back up, since i'm doing a tech thread on beefing them up.

 

If you mount them lower on the axle they are not loaded as much. The loads go from bending to push pull. Hard to see that it makes much difference but it does. A friend has a 383 SBC in a 32 5W and drive the devil out of it. I mounted them low. No problems.

PS, This also solves the interference in 32's with the frame.

PS2, it lowers the roll center and you also can leave the rear crossmember as is and not flattened. It also lowers the car.

 

What year and make rear end did you use for this build. Also was the rear end narrowed.

Frenchy

 

The height at which you mount the bones has no bearing on it's ability to resist bending. The rear end moment force needs to be opposed in order to spin the tires. Whether the bones are mounted just under the axle, or 8 inches under makes no difference. The moment force is the same.

 

Oh,oh....you opened a can of worms with that one. Prepare to be corrected

 

It's already a "can of worms" but he's right.
I also think that there is some confusion with regard to keeping them "triangulated". It's a good idea because it allows the rear end to tilt or pivot with less binding but it won't prevent those long and nearly round tubes from bending when enough rotational force and torque is applied.
There is more than 1 force at play in this area and a whole lot of factors (tire size, gear ratios, etc.) that I still haven't seen mentioned.
And incidentally, I have at least 3 pairs of '36s, all with mountings intact, that have bent and twisted tubes from (in my opinion) too much torque.

 

It is an early Bronco. It is a 3.70 open rear.

 

As asked in the very first post on this thread, and several times after that.. If you have at least 3 pairs of failed (Specifically)1935/36 Rear wishbones as you stated. Please post up pictures of them,... please include detailed pictures of the failure as well as pictures or detailed description of the type of mounting at frame and rear axle. And the conditions in which they failed. I would greatly appreciate it.

Also , if you would be willing to sell them, please let me know what you would want for them, as I (as well as a couple friends of mine) would like to get a really good look at the failures.

Looking forward to seeing the pictures. Thanks

 

Rut roh!

 

Yes, these are stock and as I said, I don't know how they were damaged. Of the 3 sets I have, one set was fairly evenly bent and has been straightened, the other had been shortened to about 42" had bungs with large aircraft rod ends and were both "wrapped" so I cut the tubes off and just kept the forged ends.
I don't have the evidence you're asking for in the form of a photo but you should know that I've always loved the '36 radius rods. I don't think there's anything better looking or better suited to a traditional hotrod but I don't think any of us can afford to overlook the fact that if we use them inappropriately, they will be a weak link. Then and now, it's relative to how much force they are subjected to and no one is saying that it doesn't take a certain amount of torque and traction to over stress them.
The reason PSI started manufacturing their own heavy duty version of the '36 radius rods and spring hangers back in the 60s was that the original Ford parts were not holding up to increased power and drag racing. Jim Gordon who was at PSI back then told me they saw plenty of the kind of failures we're talking about.
What I am most confused about are the dimensions and examples you're using when you talk about wall thickness. 1st, the rods in my picture I ***ure you are under 0.125 (I can see the thickness at the edge of the bolt hole) and so were the others that I have cut. I would say they're closer to 0.109. You say they're 0.160? Were is this difference coming from? Don't these look like '36 rods? Was there a "heavier" version that I've never seen? I don't get it, but I contend that even at 0.160 these tubes would be a weak link. Furthermore, "most hairpins" and "the brackets on late model suspensions" are not a rational comparison because neither uses a 60" long single tube that is only a slight oval taper. There are some great examples here of ways to "improve" them.
I know you're not asking for "opinions or stories" and you've heard enough of mine but I think its gonna be hard to find photos of mistakes most guys learned from back in the 60s.

 

Hey Steve !

You really didn't expect me to leave this all go unchallenged did you ???

First of all,.. So far nobody has been able to offer any real evidence of these bones failing,... And there are plenty examples of other components that have failed over the years recorded in photographic imagery...

These bones have been used by many Hot Rodders over the decades with nothing but flawless performance to report,... (I am in fact one of those guys),... As badly as these wishbones have been put through the ringer, you would ***ume the swap meets and s**** yards would be littered with failed examples of these wishbones being pressed past there structural abilities,.. and they would be all but worthless.

From my personal experience, There are far more success stories ( with undeniable proof) then failure stories ( without any proof at all).

As far as P.S.I. is concerned,.. I worked at a really large speed shop in the 70's and we sold a TON of P.S.I. components, During that time I had an opportunity to talk a number of times to Gene Scott, And have talked to Jim back then, and again sense Genes death. Gene was successfully manufacturing and selling Hot Rod components based on Early Ford suspension,..... The "much heaver" ends were cast, Not forged like Henry's
And you were sold a 0.125 wall, seamed straight oval tube to weld on at any length you wanted. ( I actually still have 2 examples of the P.S.I. units). Gene developed and sold these based on the demand and popularity of the original 1935/36 rear bones. ( As well as a number of other style suspension mounting hardware for hot rods).

Next you stated :

"What I am most confused about are the dimensions and examples you're using when you talk about wall thickness. 1st, the rods in my picture I ***ure you are under 0.125 (I can see the thickness at the edge of the bolt hole) and so were the others that I have cut. I would say they're closer to 0.109."

Steve,... Man I wish I had your eyesight !,... I had to rely on a Lufkin 0-.500 Tubing micrometer and a Mitutoyo dial caliper. and they both came up with the same thickness !,... (My son is an inspector at a Machine shop that specializes in Avionic contracts,... And he calibrates them for me from time to time, at least once a year). I only had 3 pair of cut off ends and the rest of the wishbones from the last pair of cut off ends to compare. They were all within 0.005 of each other.
And what bolt hole are you talking about ? The one you got your eyeball reading from ? the one for the mechanical brake rod ?,.... or the one just ahead of that?.... I am just totally amazed you can actually just look at something and say they look to be 0.016 thinner than you thought they were when you looked at them the first time !,....
Wish I could do that !!!

As far as your statement " I contend that even at 0.160 these tubes would be a weak link. Furthermore, "most hairpins" and "the brackets on late model suspensions" are not a rational comparison because neither uses a 60" long single tube that is only a slight oval taper."

Wow !,... I thought that "slight oval taper" more than doubled in height from front to back ?,.. And if the rotational force of the axle during acceleration causes the leading edge of the wishbone to lift,.... doesn't the principals of leverage come into play?,.... reducing the pressure at the leading edge (front pivot location) ???,.... enacting weight transfer?

There are a plethora of parts manufactured by the Auto industry that was never intended to do a certain thing,that they find themselves doing, and doing it quite well,.... It is the entire essence of Hot Rodding. Flatheads that were expected to preform at a grand total of 85 horsepower have been pushed to very impressive numbers Ardun heads, Superchargers all with only 3 main bearings holding the crank.

Steve,... you must be scared to death to use Ford front wishbones !,.... because like stated before,.. they have a thinner wall and there are some really serious and diverse pressures applied to them. IMHO


Suddenly,..... I think I would like some ,..... popcorn !!!