Hey Mickey,

You owe me no apology. It's my poor reading skills that are at fault and besides I'm a new guy here and you guys are the experienced experts.

I'm glad to have found a site where I can learn something. Some of those other sites are about conforming to their ways and beliefs or leave. I left.

There are some real dim bulbs out there. One site about T-buckets argues whether shock are even needed. I believe the concept of shocks has been an accepted design concept for what? About a hundred years?

Gentlemen, I apologize for being so far off topic.

Thanks,

Doug

I can't tell what size bolt is in your lower control arm, but I'd use at least a 5/8".. Will there be softer bushings of some sort? It looks like you have metal mockup bushings in place.


When it's done, I'd ride in it.

Like anything, inspect it regularly.

Later, mikey

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Heres to you Deuce...."you da man" One of the best threads ever.
I think to many people think "it can't happen to me" kinda thing,I'm sure you opened a lot of eyes out here.
Years ago my bud had a T coupe all fancied up with tube axle.The weld broke at the kingpin part,hit a culvert,did a endover,fuel pouring on their heads.Very scary,luckily no one hurt.

That is a flawed design for sure. It puts too much stress on the lower X-member/A-arm mount. You could improve it quite a bit by adding in another bracket behind the lower A-arm hinge bolt. The bracket would preferably bolt but could weld to the frame and extend down so the A-arm bolt would pass through another sleeve in the bracket. Bolt gets to be pretty long! This would spread out the torsional forces similar to the function of the MII strut rod.

willys, could you draw a sample of what i think you are refering to as a supplimental rear bracket for the lower arm mount ? mikey, the lower mount bolt is 5/8" and there will be urethane bushings used upon final assembly. i have aluminium mockup bushings in now. thanks for the replys !

I found this drawing somewhere on the net. Isn't it done by a person on this forum?

that's the idea i was thinking about ! approximately how much [percentage wize ?] would that increase the design strength ? i already have the "horizontal gusset" on the outboard tubes, and was planning on adding the vertical one. what would the thickness of the bolt end-to-frame gusset be ?

I am no engineer, but I would think not nearly as much as the proper strut bar would.

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any other ideas ?

I would go as thick as you can based on available bolt lengths. I think I would put the vertical gusset on the back support rather than the tube (assuming you are only going to use one).
This is what I intend to do with my TCI unit. Once I get everything mocked up, I am going to see if I can add a similar support to the front mount as well.
IMHO, the real problem with these types of front ends is the fact that the bolts are in single shear at both ends. Putting the extra "end to frame" brackets on makes the design double shear - far superior.

Yes, this is exactly what I meant. However, it does need two gussets on the front. Also as mentioned above, I would weld this all to a 3/8" thick piece of 2"x3" angle iron and bolt it to the frame w/ 4 1/2" grade 8 nuts and bolts. Frame metal is just too thin to hold a butt weld on a highly stressed part like this. As mentioned in the sister thread to this one, one of my quests is to go to rod runs and point out to rod owners their single plate strut rod brackets that have cracked and broken off the frame.

That's pretty much the same idea for an additional brace I talked about back on post 38.

Except I would just run it back into the crossmember, instead of up to the frame. Seems to me that the more severe impact forces are pushing the LCA towards the back of the car, instead of down and away. Although the LCA inner pivot does want to move down and away from the frame because of the way the shock is mounted.


Still,I think any extra bracket that captures the ends of the throughbolt is going to be a help.

As far as getting the throughbolt size larger, but being limited by the lengths commercially available, I seem to remember installing a MII front end with a 3/4" through bolt of sorts...it was a 3/4 rod with male threaded ends and acorn nuts on each end.

My memory could be failing me in this instance, in regards to the bolt diameter, (it could have been a 5/8"), but a through bolt made that way in 3/4" doesn't sound like a bad idea, being as how we are looking at these MII front ends and their shortcomings.

Later, mikey

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Mikey,

It ain't the TCI that are 3/4 - I checked mine and top and bottom are 5/8 NF. And - for a light car like my '31 roadster, don't have a problem with the design or size of the fasteners. There are just too many thousands of TCI's out there that have NOT failed for me to worry about this potential. Quite frankly, after looking several times at the car Deuce pictured - I'm convinced the car owner hit something and broke it and caused the crash. If I was to build a heavier car, then I might consider additional bracing.

Dave

Powerrodsmike, I think you are right about the additional gusset.



It would help as shown, but adding the brace toward the center of the car will put it in compression if the load is applied from the front (most likely). The bolt in double shear will be good.

As far as length of the bolt, 9 inches was the longest I could find on a cursory check in McMaster.

In reality it is not necessary to thru bolt this. If the tube were either plugged and tapped or made of thick wall and tapped, or just solid drilled and tapped it would be ok. There really isn't much force trying to pull the bolt out. Getting it to stay tight in any case is more of a problem.

You can get weld bungs for this too. This is what was ripped out in tension on our sand buggy. Equavalent of ripping the rod end out of this a-arm shown. About 83,000 pounds force depending on the value of 4130 tube. the tube failed not the weld or rod end in this case.

With the as shown modification I think the front rod end, bolt or a-arm tube would fail before the rear due to the single shear and tension from front impact. You can add an awful lot of steel and not really improve this. It's just hard to beat the strut rod. Ford engineers did their home work.

The best you could do I think is as shown with Mikey's additon integrated into it.

I'm working on a streetrod for a customer that not only has a strut rod but an additional diagonal brace from the front crossmember to the strut rod bracket. Very solid mount.

With these mods the front suspension will be much stronger. A direct impact ripping off the entire side will be huge. You will probably roll or at least spin around. You had best be well belted in. Your head is probably going to bust the side glass too if the impact is on your side of the car.

I didn't design that drawing or extra tab, I only wanted folks to know that others, with better minds than mine,, had come to the same conclusion as I.

I want to be in GOOD company here.

Bentwings is right, how many cars have 2 bolts with tabs/ threaded bosses on each side of the rod end holding the LCA on. It seems like that is a widely used, trouble free, joint design. (which, when one part is made stronger, puts the stress on something else )

I think what it comes down to is the end use of the car, the weight of the car, overall configuration and how fail safe you want it.

I know that this thread has not changed my mind about the many design interpretations of the MII, as offered by various companies, some have flaws which need to be watched,, some are well suited for the application, but I, personally, had already started looking at alternatives, especially on heavier cars.

It just seems that the size and proportion of all of the components limits it's use in all applications. Even with strut rods.


Last May, a guy who came in my shop looking for a suspension upgrade on a 56 chevy. I asked him how he used the car.

When he told me that he liked to hammer that old Bel Air around the back roads of our coastal mountain range, the first thing I said was " it ain't getting a MII"..

That car got a suspension based on 81 camaro parts.

Still, I need to get his car in for a 5000 mile checkup too.

Later, mikey

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No one is completely useless..They can always be used as a bad example