Should I be pissed or is this my fault?

It seems like it is just a matter of inferior hardware. There has got to be a pin/bolt/rod that is made to withstand the stress of that application. But that one wasn't.

 

Here's the offending part

 

Glad you're O.K. Scott, but living in Bay City I'm suprised it did'nt happen sooner with our roads.

 

doesn't look like a grade eight bolt from where i sit.maybe someone subbed when building the kit.

 

My two cents would ask just how rough were the railroad tracks?????How fast were you going?yadayadayadaEvery body want to Jump on Speedway for something thats probably not their fault.Need to exercise SOME care in your driveing.Hell,I broke a muffler hanger on my NEW car on a railroad track.I dont blame the car manuf!!!!!!
I should have slowed down over the tracks!

 

Yea that's the cast/pressed one like I thought. That shank should never break off, if there were teriffic stresses going on, the shank should pull out of the casting first.

 

don't blame the railroad

 

My car rides 5" off the ground, I have to slow to around twenty mph or so. The tracks weren't particularly nasty compared to the other ones in town. Even had that fancy two foot rubber aproach strip on road either side of the track.

I think only one person has jumped on the manufacturer so far. And it wasn't me.

 

looks to me like it snaped off at the first thread, at that point its more like a 3/8" bolt.

 

should that perch bolt pivot with a wish bone front end.it would seem to me that the up and down movement of the axle would be trying to twist that bolt.a four bar would not have this problem?all the twist stress would have to be taken up by the shackles.the more up and down movement of the front end ,the more that bolt is under high twist .just a thought.

 

I agree. If the perch were allowed to rotate, a lot of twisting stress is avoided.

 

Are you sure that it isn't a one piece casting, with the 'bolt' area machined afterwards ?

If it is, that would certainly explain it cracking and breaking like that.

 

NO, perch bolts do NOT need to rotate.
Ford didn't build cars with pivoting perch bolts,
and they didn't have any problems.

Having parts rotate,without a proper bearing surface,
will cause wear and eventual failure.

Why do people think that a leaf spring can't twist, even small amounts ?
--------------

Where was this broken piece manufactured, and to what specification ?
What sort of testing do these components have to pass ?
Are random samples tested from each production run ?

 

Either way man, you have gotta have some good karma stored somewhere.... thank god you didn't have a serious accident. You should call Speedway and ask them about it. They should be able to track the batch # of when you bought it to see if there have been any others.

Mott

 

DING ! DING !
That is it. The end of the thread is the stress riser.


Any chance they were cast by the same guys Speedway had
making the Pitman arm than snapped off someone's car ?


Ever notice the OEMs don't use cast iron suspension or steering components ?
Why is that ?

 

Man I hope that is more than a threaded casting.

 

Lucky, I'm trying to visualize exactly where the friction shock link connected. You make an interesting point about the effect the shock may have on the mount.
A 90/10 shock allows for initial movement and then applies damping (~90&#37 whereas a friction shock damps on each direction (compression too).

 

be pissed and thankful that you are okay...this could have had a much worse ending...yup we should all be doing regular inspections on our vehicles because this shit happens

 

I don't see a seam where the threaded part enters the casting......

 

Check where the Red arrows point.

Look like parting lines in a casting ?

 

Don't blame the company. The object of a scientific investigation is to analyze the data, and come up a theory on the cause. The goal is to determine if the set of events that caused the failure were predictable given the materials and the conditions of the failure. You want to determine if there is more torsional stress on the bolt than it is capable of handling, of if there was enough slack for it to have longitudinal events that exceeded the rating of the material, and if the design of the piece is under- engineered given the properties of the material in use. The weight of the car is distributed in a front engine vehicle with a bias toward the front because of the engine. This weight in a forward and up and down motion combined, as when you are driving creates various cycles of stress that can exceed the design that was engineered in the bolt. The bump was an abberation, an event that might have not been calculated when the piece was engineered. Also, in welding heat is generated that deteriorates whatever properties that might have been present when the bolt was manufactured. Add to that, fatigue, and you have a convocation of elements that can wreak havoc on anything that is marginal. One bolt that is momentarily compressed and then stressed in the opposite direction seems to me the basic problem in the design. If, as we know the cycles of circular motion of the mass (the vehicle) as it rocks back and forth are added, you approach a critical point every time you drive. (And, if metal is plated there is also the problem of nitrogen embrittlement. I can't tell by the photo, but chroming front end parts that are under stress is always dicey.) The weight you give seems heavy in view of the fact that in California there is (or was) a law requiring any motor vehicle that weighed over fifteen hundred pounds to have fenders, which made many early roadsters illegal, and most of those on the road without fenders, today. The point being that your front end design, while traditional is not safe. The concept of the so-called 'suicide front-end' actually appertends to the fact that when these type front ends fail they usually come straight up and straight back through the windshield into the driver's face resulting, generally, in a fatality. Instead of being pissed, you should be thankful you are alive and smart enough to ask others about the problem. If you were my brother, I would say, "Looks like it's time to go back to the drawing board." Rather than trying to correct the problem of the bolt, you should work on the design. Or Speedway should search their own souls in selling items of this nature, considering the potential for failure, and the potential for fatalities. After all, it does hold up the car. Some of the old timers didn't get second chances like you've been offered. It's about smarts, or the old saying goes: "Ingenuity in action." First the ingenuity and then the action.

 

Unkl Ian you're ahead of me..parting lines? Is the shank pressed in or just part of the casting?

 

I dont care if its the people that speedway hired to make the part of speedways fault or even lucky77's fault for doing something alittle off.. its enough for me to buy my suspension parts from someone else even if their alittle more $$.. Thanks for the post and glad your ok.

 

I just went out and knocked the nut and remaining stud out of my batwing. I think it's weird that stayed in place after the failure and the ride home on the rollback. Might be kind of hard to see my camera is only 3.2 meg but maybe this little piece can tell us something?

 

There is an extra hole in one of the shackle plates. The rod end in my shock link bolts into this hole.

 

You could very possibly be correct, however this is a kit that Speedway sells with all the components in one package i.e. shackles, axle, spring, and all the hardware. I know Speedway sells a million of them.

 

I don't see any porosity in the remaining part of the stud in the little pics. The little piece stayed in the batwing because it became stretched a little out of shape where it broke off.

 

What was the angle on the shackles at ride height ?

 

Your spring perch coming out the side of the bat wing like that is a lot of stress on the bolt.Like the other guys said if it is over tightened it could of started the stress crack that eventually broke when you hit the bump.I would consider mounting the perch so the load isn't stressing the bolt. Also any hardware store bolts are risky for suspension .Even though they say grade 8 or 9 there are a lot of China made inferior bolts with poor grade metal mixed in.Ask any aircraft mechanic,they will set you straight.This is serious stuff ,only buy the best when it comes to suspension , steering and brakes.