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rear poly bushings on outboard end of CA


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I cut my front LCA of the same as you have done on the rear. I then stuck the threaded tube end into the square section, and formed (with a hammer) the square tubing over the tube end and welded it all up. I had to cut a Vee to go from square to round in the LCA, but no big deal. This acts like a plug weld on the side of the tube end as well. ou could do something similar for your tube ends. Bending the steel is easy, especially with a torch (I did not have one at the time).

 

Another option isweld the tube end into a short stub round tube, and use a hole saw or die grinder to cut a hole into the LCA to mount it and weld it tight. I would still lean towards forming the metal over the tube, instaed of just capping off the ends of square sections. If you want to cap the ends, at least wrap the caps over the top and bottom of the LCA, and be judicous in where and how you weld it. I used TIG to weld mine up, ensuring good penetration and control...MIG would work fine if you are comfortable with your setup and know how good your weld is after welding (I am afraid there are a lot of people who think their MIG welds are great, when in reality they are weak and cold).

 

Joshua

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That's pretty much the way my fronts are done too. I had a machinist do them for me, and he took a 1" OD round tube (I think) and welded a tube end into it. It fit really tight, so he hammered it in and did a couple plug welds around and then welded around the end.

 

I am pretty comfortable with my welds, I definitely don't think they're cold. If anything I usually run them on the hot side from what Miller suggests on the side of the welder.

 

I'm leaving town so I'm going to deal with it when I get back, still thinking that honing the outer end might be the way to go from a simplicity standpoint.

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I have some arms I'm going to eventually modify for a friend. I was looking at them last night thinking about ways to do this. I thinking I'd cut the arms across the flat plate and weld on a piece of square tube. This tube would be hole sawed to hold the heim adapters Jon showed further up the thread. Not sure that makes sense but it's clear in my head :-)

 

Cary

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I think I follow. So the tube would be mounted front to back, and the adapter would be side to side? The adapter is 1" OD round. I do have some 1.5" square tube. That might be an easier way to do it. Then maybe form the top of the tube around the adapter as Jolane suggested.

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I have some arms I'm going to eventually modify for a friend. I was looking at them last night thinking about ways to do this. I thinking I'd cut the arms across the flat plate and weld on a piece of square tube. This tube would be hole sawed to hold the heim adapters Jon showed further up the thread. Not sure that makes sense but it's clear in my head :-)

 

Cary

 

Cary,

I think I understand what you are saying, but what would a tube buy you over just a flat plate on the end? It might even be possible to modify a stock arm to look like the Modern-Motorsports arms at the ends. Seems like you could put a 3/8" or so plate on the end and double nut the heim. I have not seen a MM arm in person, so I have no idea what thickness they are. I also don't know if this would be a good method or not, but something else to consider. Personally I like the threaded tube ends, although adjustment does require taking things apart first...

 

Joshua

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I think I understand what you are saying, but what would a tube buy you over just a flat plate on the end?

 

The adapters that John has will be stronger if they are held in a couple of places. I think they could be welded into the stock arms. The tube idea was to simplifiy the fabrication and make the arm stronger. It's a lot easier to use a holessaw on square tube and mount the adapters and then weld this assembly to the arm.

 

In the pic below the yellow bits are square tube and the red bits the adapters welded into it. You can see how this part bridges the tubing of the stock arm.

 

Personally I like the threaded tube ends, although adjustment does require taking things apart first...

 

If you use a toe-adjuster or better yet a threaded bushing with left/right threads you have adjustement on the car without taking anything apart.

 

Cary

arm_thumb.jpg

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The adapters that John has will be stronger if they are held in a couple of places. I think they could be welded into the stock arms. The tube idea was to simplifiy the fabrication and make the arm stronger. It's a lot easier to use a holessaw on square tube and mount the adapters and then weld this assembly to the arm.

 

In the pic below the yellow bits are square tube and the red bits the adapters welded into it. You can see how this part bridges the tubing of the stock arm.

 

 

 

If you use a toe-adjuster or better yet a threaded bushing with left/right threads you have adjustement on the car without taking anything apart.

 

Cary

 

Cary,

Yeah, I guess that would do a good job at strengthening the arm. I would recommend capping the ends of the tube as well.

 

By toe adjuster, do mean inboard behind the diff instead of adjusting everything in the LCA's (I think it is BlueOvalZ who has a nice setup like this)? This method does shift the wheel in the wheel housing though due to the moment of the LCA. If this is not what you mean, I guess I don't see how you could make the adjustment. I guess in the end, how often will this be adjusted anyways once set-up? I assume it is set it and forget it, but I don't race cars...

 

Joshua

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By toe adjuster, do mean inboard behind the diff instead of adjusting everything in the LCA's

 

No, by toe-adjuster I'm talking about a specific piece that has left/right threads sorta like a turnbuckle. I do agree once this is set it isn't that likely many people will be changing it.

 

Cary

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No' date=' by toe-adjuster I'm talking about a specific piece that has left/right threads sorta like a turnbuckle. I do agree once this is set it isn't that likely many people will be changing it.

 

Cary[/quote']

 

Cary,

I am not sure I understand how you could add this to a stock control arm. For the front, sure, but the rear LCA has to control more than lateral loads. The rear has to control the fore/aft tire movement (accel/brake) as well, and therefore needs to have shear strength built into it. Of course it also has to keep the wheel pointed straight (toe).

 

Maybe I am missing something, but I think that a modified arm will have to be removed to be adjusted. In the end, I don't think this is a big deal, since the frequency of adjustment is minimal...

 

Joshua

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The adjuster I'm thinking of is a shell. On the outside is a set of threads and on the inside is another. One set are right, the other left. This allows the unit to operate like a turnbuckle in a very limited space.

 

The toe-adjuster was shown on another pair of fabricated arms in one of the threads where rear arm options were discussed.

 

Hope that helps,

 

Cary

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The adjuster I'm thinking of is a shell. On the outside is a set of threads and on the inside is another. One set are right' date=' the other left. This allows the unit to operate like a turnbuckle in a very limited space.

 

The toe-adjuster was shown on another pair of fabricated arms in one of the threads where rear arm options were discussed.

 

Hope that helps,

 

Cary[/quote']

 

Thanks Cary, that helps a lot! It is a differential screw! I didn't realize that they made then suitable for suspension components. Do you have a source for them (or a link to the other posts about them)?

 

Thanks again,

Joshua

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I have similar reservations about using a turnbuckle as the sole support for the rear arms. I would rather rely upon good nuts on ether side of the threaded portion of the spherical rod ends. My proposal would be to allow the rod end to slip into a hole in the side of the square tubing, and then nut it on both sides of the tubing wall. This way, the rod end adjustment could be done without removing the end from the spindle.

 

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Blue,

 

I vote to change the tubing to thick steel for that method. There is a lot of forces there, so the metal needs to be thick and strong. Basically, this makes it look like the MM design. In fact, replace the Heim's with the stock car bushing assemblies (I don't know what they are called, but have a "bolt" welded to a tube" and it would basically be the same thing.

 

I hadn't considered modifying my rear LCA's before this thread. Now maybe I will consider it. Since this is a street car, anyone think I need the adjustment at the wheels, or would the center adjuster (like Blueoval's) work fine? I have no appreciation how much the toe can be off stock.

 

Joshua

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The purpose for this modification is the reduction of stiction. If you just want to adjust toe, our toe adjuster mechanism works better and is easy to fabricate. I think we have 4 or 5 people running various designs now, but the original thread was Terry, myself, and Jeromio.

 

With respect to how much it could be off, Jeromio's car had a badly manufactured strut and I think he ended up needing both the toe adjuster AND offset bushings to correct the situation. But for a normal car the adjuster doesn't require much actual movement to get the toe where you want it, it's super easy to adjust, and is easier than any of the ideas you guys have posted for adjustable toe on the arm IMO.

 

It's kind of like buying AZC control arms to adjust camber. Yes, it can be done, but it is so much easier to use a camber plate! If I do end up with rod ends on the control arm any adjustments made will be to change the track.

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Thanks for the explanation Jon. I am trying to figure out which method I should use for my street car. I had a feeling this really applied more to a track car. Good luck and let us know how it goes (and which method you use).

 

Joshua

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  • 2 weeks later...

Well I went out to the garage for the first time since getting back into town. Looks like the 1.5" square tube I have is too deep, and that the ends won't hit the back side of the tubing. Checked http://www.onlinemetals.com, they have a 1.5 x 1 x .065 that should work. A foot of the stuff would run a whopping $1.50, so I think I'm going to order it up. That puts me off of that project until tomorrow though. I'm thinking that this might just be the way to go because the ability to adjust the rear track might come in handy someday.

 

Also considering scrapping the spindle pins for a couple of 5/8" bolts. The issue there is that the spindle pins will be longer than necessary if I set the rod ends so that they sit flush on the end of the strut, so a 5/8 bolt might be better. Wouldn't have to make spacers for the end of the pins.

 

Anyone see any advantage/disadvantage to moving the rod ends closer to the strut with no spacers vs having them at the distance originally designed for the bushings and using spacers?

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Anyone see any advantage/disadvantage to moving the rod ends closer to the strut with no spacers vs having them at the distance originally designed for the bushings and using spacers?

 

The only thing I could think of might be to use spacers to change the side to side track width either to tune balance, square the car up, or get the strut tube fore/aft angle equal.

 

I guess it depends on how precise you want to be on setup. I would recommend a safety washer on the outside of the heims.

 

Cary

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I didn't even think about adjusting wheelbase side to side. Right now my car is straight, but who knows what will happen later in it's life. I think I'll use spacers.

 

Do you think the safety washer is still necessary if I use the 5/8" bolt? The head of the bolt and the nut would certainly be big enough that it couldn't slide through the rod end.

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Anyone see any advantage/disadvantage to moving the rod ends closer to the strut with no spacers vs having them at the distance originally designed for the bushings and using spacers?

 

Moving the rod ends closer to the strut would increase the force through them due to being a shorter moment arm resisting the tire wanting to spin around the strut. For the small amount of movement you're talking about I doubt it would be much but pretty easy to figure as it's just a ratio of the old vs new distance with respect to the centerline of the strut. Without spacers would save weight but we're obviously talking ounces here so I doubt you care.

 

Cameron

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Do you think the safety washer is still necessary if I use the 5/8" bolt? The head of the bolt and the nut would certainly be big enough that it couldn't slide through the rod end.

 

Yes, if the ball pops out you may lose containment. Most sanctioning bodies require safety washers for single shear mounting. I figure it's cheap insurance you hope to never need.

 

Cary

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