Technical Upper Control Arm Question

I am working on a 61 Buick LeSabre. I installed dropped spindles, disc brakes and new spring and took it to the alignment shop. First, we found out it is very difficult to get to the upper control arm bolts. It's a two man job. Next, we found out that these cars came with NEGATIVE caster. In order to get the camber to -.3 degrees, we had to stack up a lot of shims and the most caster we could get was -1 degrees. I was hoping for +2, at least.

The control arms are shimmed out about as far as is reasonable, so I am at the limit of the present components. As far as I can tell, nobody makes any aftermarket control arms for these cars so I got to doing some "imagineering". What if I cut the upper control arms and shortened them enough to get me close to zero camber and a couple of degrees caster. That would mean shortening the rear side more than the front side. Have any of you done this before? Am I missing something? Why wouldn't this work.

 

Haven't done this myself, but on tri-5 chev forum, some guys used to cut, tweak and re-weld the rear upper control arm mount on the ch***is, to allow more adjustment. Longer bolts on the upper mount would also allow a few more shims. Although not familiar with your actual setup.

 

Any chance they make offset control arm shafts for the LesSabre? Any chance a set for a 55 Chevy would work since they do make them for that car. How about moving the upper ball joint mounting ? that might only take some grinding of the hole,and welding the bolt holes shut then redrilling them. Welding control arms just doesnt sound safe to me.

 

Could you redrill the lower control arm mounts and move them instead of the top control arm?

 

Buick was still in the "negative caster" mindset when the 1961 suspension re-design was done, which carried through 1964 on the LeSabre. While I don't see why it should not work, you could always get another set to play with. French Lake auto has a couple of sets on Evil Bay currently. Could start by shortening the front leg just shy of the thickness of the shims and an additional 1/8" on the rear leg for caster. As long as there is no ball joint bind, it is worth a try.

 

That is exactly what I was thinking, Bill! I have a new idler arm coming Tuesday to replace the worn one. After I set the toe and drive it, I will decide whether I need to try to get more caster.

 

Most cars, with original type suspension, we shoot for 0 to 1/8 degrees positive on camber and as much positive caster as possible, which is usually not that much, like 1+ left, 1.5 + right.
The caster may even end up less than that due to old suspension designs and tire location in the wheel well.
I'm not a big fan of running negative camber unless it's a canyon carving type of car that wants go around curves at high speeds.

Bill

 

I think we can agree that -.3 degrees is virtually zero camber. Heck in 1961, they couldn't even measure + or - 1/8 degree accurately.

 

Actually, -3/10 is a lot of negative camber in my book.
You can easily see the tire leaned in at the top. Inside tire wear can result and visually looks bad. That's how Fox bodied Mustangs looked and looked like they needed front end work and ate up front tires.
I use a old fashioned Wheel O Matic bubble gauge from the 1960s with caster/camber plates, on a level lift. So I guess I can't measure them accurately.

Bill

 

I deal with this all the time. Infact have an old chevy coming into the shop next week that has -1° negative camber and no place to go.

What happens is over time the front crossmember settles. When it does it slowly goes negative so you need to find a good frame shop that knows how to do it.

What you do is throw a chain, make sure it's high tensile, around each front bolt on the the frame where the upper arm bolts on, hang them to the outside of the frame rail and down.

Take a heavy iron knee and tie the chains to it. If the chains are in the right position it will put the iron knee right under the crossmember. Put a 20 ton ram on top the knee and a big heavy plate between the ram and xmember, slowly jack it up.

By doing it this way you slowly spread the xmember back out. It flexes alot, but jack it up to about +2 camber and let off, now read your camber. I try to get a good +1 to +1-1/4 camber with the shims maxed out.

Just keep jacking it up in 1/4 to 3/8° increments until I get to the 1° to 1-1/4° when the jack is off.

Then I start taking shims out of the rear ear to gain caster and set camber a little fat +1/2 camber in the left/drivers and +3/8 in the right/p*** side. Set toe to a 1/16" in and go drive it. I find it settles to about +5/16 left 3/16" right. Your done.....

40 yrs and more than I can count and never had a problem doing this.... and yes it stays. It's like any frame work, once you pull it and straighten it, it should stay. Of course in another 20 yrs it may need it again.


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I use and prefer a 1940's era beeline hand gauge every day and can easily read 1/16° degree. Yeah have fancy bubble rim gauges etc but still prefer the plump bob hand gauge. Easy to read, even easier to true and check for accuracy.

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I run -3.0 on my Falcon.

So yes -0.3 is statistically indistinguishable from zero.

 

At your camber, and say with a 27" tall tire, to pick a number, the top of the tire is 0.070686" inward from the center of the tire, or 0.141372" inward from the bottom.

For perspective, I am running fine, with 20,000+ miles on my tires, with the top of the tire 0.63413" inward from the center, or 1.26826" in inward from the bottom.

Oh and corners best when it is 1/16" toed-OUT.

Alignments are funny, and very few understand them, or know that skidpads and real-world results are not lies.

 

I was a hard core autocrosser for about 10 years. I understand. I spent a lot of time tuning my car.

 

So Gimpy, what do you think of the idea of cutting up the stock control arm and moving the upper ball joint location to get me where I want to go?

 

I would never cut and modify anything if it's a simple fix like finding a frame shop to just push the crossmember back up into place.

Safety, drivability, cost, time and did I mention safety? Are all concerns when it's just a simple fix.

No offense but that's part of the reason there are so many hack jobs on the road today, because no one wants to fix it right and always looking for the easy or cheap way out. Then we end up with some of these hack jobs driving down the street heading at our families at 65 mph.

Of all things to do right it's the frame, suspension and brakes. These are the foundation to a safe vehicle, for both the occupant and those around them.

Again no offense but I see unsafe vehicles stuck together alot, so bad so that a few were chained to a large tree until a wrecker could pick it up because it wasn't leaving our shop under its own power to be put back on the street with families driving around it.

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It is kinda brute force. Yeah, it can be made to work, but unless you are hyper precise, you are going to end up with two different control arms.

I do most things over-the-top, and would probably make adjustable control arms.

If you have access to accurate tools, and are confident in your methodology, then have at it.

The amount that you would need to "edit out" is fairly small, so that they end up where they can shimmed for exac***ude.

 

I have built close to 160 vehicles that had control arms that I built myself. Zero failures.

I have shortened, lengthened, and otherwise modified just about every single critical suspension element that you might find on everything from a lawn tractor, to a trailer-truck. Also zero failures.

Never ***ume that someone will do a poor job, or does not understand the gravity of what they are working with.

 

Why in the hell would you want 3 degrees negative camber on any street car? That would eat a pair of front tires in a hundred miles. Answer that with an honest answer and not to get ugly wheels under the fenders.

The Buick and Cads in those years ran negative caster and were damned good road cars for their time. I alignedd a lot of them in the 70's and they didn't have any real drive down the road issues and a lot of them spent a lot of time n the fast lane.

If you don't want to eat up tires on weekly basis set the front end with 1/4 degree positive camber on the left wheel, straight up 0n the right factory setting on the caster and 1/8 toe in and quit trying to reinvent the wheel.

 

I would only trust ME to do this.

 

I ***ure you, I know what I am doing and am capable of doing this and having a safe automobile. I do all of my own mechanical work so that I know how it is done. I like ME a lot.

 

I only build cars for myself that have high-performance handling. Even my Model A pickup will best 1.0G on an 100-foot skidpad. If it doesn't, it will get done over until it does.

I just checked the odometer, and somehow I have travelled 21,868-miles on these tires, with only slight wear on the inside.

Must be some kind of miracle.

Or is it....

 

I take people at their word.

Carry on. Be not discouraged by those who ***ume that what they can't, or won't do cannot be done.

 

I wonder how the naysayers would feel if the found out that I have not only made control arms, but have also fabricated spindles, too, including on my own current build!

The horror.

 

My car has a front end out of a 69 OT Holden sedan (GM Holden Australia) which has positive caster, I couldn't get + caster on one side, no matter how hard I tried.
The next model Holden had negative caster from factory, so I set my front end up to these negative specs as well.
I am a retired mechanic, and have found there is no problem with handling or steering with this setup as the suspension is matching both sides for negative caster, also, I have not had the tires wear out prematurely over the 20 years my car has been on the road..

 

I've built plenty of parts, suspension included. Some on sub 10 second street cars but I am also aware it takes experience, knowledge and lots of checking and double checking then checking again before I strike the first arc.

It also takes an understanding of front suspension geometry along with the loads that's going to be put on that part.

I built lower controls arms and ladder bar rear suspension that run on a street car that consistently runs 8:80's in the quarter that him and his wife drive every weekend all over the country side. I also understand the loads put to the materials and welds not just from shock of tire bite at the track but everyday pot holes, rail road tracks, and just average everyday roads.

Have no problem with someone that understands these parameters but honestly gimpyshotrods how many average Joe's out there on the street that you talk to understand with clarity what's involved with your work?

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Given the industry that I am in there are more than you would believe.

 

I don't know of any aftermarket control arm makers, that recommend camber settings that negative for street use. Let alone toe out. Visually, must look terrible.
Setting up stuff for road racing and street are two different animals.

Bill

 

Not at all. It looks fine, and handles great.

The best part is not only is it quicker than about anything around in a corner, it is safer in a corner, too.

There is no difference between my ch***is setup for Skyline Boulevard, or Laguna Seca.

Oh, and there are enumerable makers of control arms, and other suspension parts that suggest both that camber setting, and toe-out.

Toe-out is the recognized fix for death wobble in solid axle vehicles, with otherwise sound suspension.

I have been curing it that way since 1985.

 

As for your ***ertion that you don't know of any aftermarket control arm makers, that recommend camber settings that negative for street use. Let alone toe out, I am about to prove you wrong.