The rear shackle in my pinto failed the other day....so I mounted it outboard of the rail and brazed the bolt on with a brass rod. I didnt think that would be enough to hold it so I wrapped an old clothes hanger around it as well.
Up here we use baleing wire. i appreciate the hummor it's needed here. I would like to say I am not against constructive criticism it is always welcome however by some on here i felt personely attacked and one even called me a potiental murderer! so yes i developed a bit of an attitude. When ATO gave his stamp of approval but said it would be even better with outside support i thought maybe i would go ahead and do this because i had originaly considered this. and no it's not an EGO thing but i felt it was secure from the get go. after all this contrversy i went out to the garage disconnected the shock absorbers (which ABSORBE shock) and proceeded to bounce the car so hard that i had the rear wheels bouncing off the ground and watched the movment of the shackels and i am convinced that it is soild and will not fail! there for i will proceed as planed!
Only thing I can see that it proves, is that you are assuming it will not be a catastrophic failure based on what happened with completely different vehicles under unknown conditions. You're right, I am extremely comfortable in my car that I have gone through front to back and know every inch of it, every nut bolt and wire in it like the back of my hand.. and sometimes I drive it much faster then 75 mph, 70-80 miles per day, and sometimes hundreds of miles on weekends, to the tune of 105,000 miles in my current Maverick, and nearly 116,000 total behind the wheel of a Maverick. The suspension under my car is not 40 years old, it was replaced completely when I started driving the car daily in late Dec. 2005, and replaced again in April 2007, and will be getting new ball joints again tomorrow. I keep a close eye on my car, over maintain it, and wouldn't hesitate to drive it anywhere, at any speed. Serious design flaws or not, the suspension design has been proven over millions and millions of miles on millions of production vehicles over the past 50 years. I'm sure there have been failures, heck, I HAVE had a catastrophic failure with my suspension, which was caused by an aftermarket part that I'm sure some engineer "doubted" would cause a problem. I went back to stock stuff, and came up with a fail safe should it ever happen again, the car has performed flawlessly since. I've seen this as well. Every trailer I've seen like that is still supported on both sides. I just don't see why it should be left up to doubt or assumption that it will not fail or will not be a catastrophic failure. I'm not an engineer and don't claim to be, but even if 100 bonafied engineers stamped their approval on that, I'd STILL add support to the other side. I trust my gut instinct, and I much prefer to have things overbuilt. I've never seen a production vehicle that was not supported on both sides. Further, post these images on any car forum, and I guarantee this will be the #1 thing pointed out as a potential point of failure (and likely argued about). If not for ego, why take the risk.. I've spoken my peace. Good luck, be safe.
Jamie Now that is how you present yourself. You did not once attack somebody in that response nor did u in any other posts u made. Some others could learn from your example. Just to be clear I never said I would do it that way.....but then again my car is being built to hang with supercars on the twisties!!!!! There just really is not as much force applied to that bolt as many think. Just to prove it I am going to remove both rear shackles on my f150 and drive to georgia for the Dixie Stampede. See you guys soon I hope..... Jamie I have seen trailers with no support in fact I sold a trailer two weeks ago that was a tandem axle I did inhert two mths ago that had this set up.....I was like wtf......
Unless someone flat out calls me out with a personal attack, I will never attack someone personally. People initiate personal attacks when they know their argument has failed. Come on down, new faces are always welcome! :Handshake
As an engineer who actually works with fasteners for a living my only concern was where it was mentioned that this was a grade 8 bolt. Grade 8 is a high alloy steel usually in the 4140 series which doesn't like welding. Now don't get me wrong, you can weld it and get a great joint with years of serice, it's just not the best material for welding. And yes I know roll cages are made from this stuff too but here's the catch. When you heat up 4000 series steels you change the internal crystal structure and without some crazy heat treating it is never the same material in the heat affected zone (discolored area). Assuming the rails he used are fairly heavy wall, the short cataliever that the bolt creates just isn't going to induce enough stress to bend that bolt. It's going to be a combination of cyclic loading from normal driving over many years and the metalmites that kill this setup in the end.
correction, I just looked at his pics a little better and the bolt isn't welded. It's going to fail from the metal mites instead. Remember, engineers are a paraniod lot, we alway lie about how far something can really be pushed. for the enginering part, grade 8 is good to around 120 ksi (proof load) with a 130 ksi yield. Yield is bad, all loading to that point will spring back, after you hit yield the bend stays. Shear is about 1/2 that (it's a steel thing). So you actually have around 60ksi available to take the point load. SAE-j429 has a lot of good info about threaded bolts. ASTM f606 is the main testing doc for nuts and bolts. Personally I'm a sadist so I work to the military standards which tie both hands and the left foot behind your back as far as what you can use for fasteners. If you want a good read check out MIL-DTL-1222. If you figure out how to navigate through that mess you don't need to do calcs you'll just know!
