Offset Upper Control Shafts

[boug58]

Hello everybody.
Has anyone heard of a offset upper control shaft, that would give me more positive camber. The frame on my 58 2 door impala was straighten body a professional body shop and they had a frame alignment machine. I brought the car to get a front end alignment, and the guy had all the shims taken out of the upper control arm shafts and said that i still had neg camber. I heard that they do make offset upper control shafts is that true. Has any one heard of this.
Please get back with me on this , my email address is dbougie@chartermi.net

 

[JimKwiatkowski]

Borg,what is your camber and caster readings?I don't know of any offset upper control arms .Have you done anything with the front springs,are they old weak springs,or have you cut any coils to lower the front end

 

[jim_ss409]

The alignment shops used to have offset upper control arm shafts available for most common makes of cars but I don't know if anybody makes them anymore. You can grind or mill a little bit off of the stock shafts, maybe 1/8" or so. That might do it if you're close. Or you might be able to spread the frame back out with a large Porta Power jack if you pull the engine but that's a lot of work too.

This problem will be amplified if you're running heavy front springs that jack the front end up higher than stock. The engine's out of my Impala right now so of course the front end is sitting high and you can clearly see this effect right now. The wheels have a bunch of negative camber, they look like this / \ when veiwed from the front.

It seems like alignment shops only want to use factory specs when setting up a front end and they seem to place more importance on getting the camber right then, if there's any adjustment room left they'll give you some caster. I'm no expert but I know one thing for sure,,, I'd rather drive a car that had a few degrees of positive caster and a bit too much negative camber. Yes, the insides of the tires would wear a little but at least It would track straight and have good road feel. By the way, the factory setting for these Chevy's calls for very little caster. This makes them easier to steer but also reduces the nice centered feel that more caster gives. It took some doing but I finally persueded my front end guy to give me about 3 degees of positive caster and the car tracks great now. My 55 Chevy with a solid front axle is another example of my "caster is king" theory. Anyone can see that it's got too much negative camber and the only way to correct it is to bend the axle.:eek: I know that sounds radical but they often do it to big trucks, no big deal. Anyway, I gave it about 8 degrees of positive caster and set the toe myself,,, It runs down the dragstrip like it was on rails.

 

[Gerry]

Offset A-arm shafts

boug58


There are offset upper control arm shafts available. Late Great/Eklers offers them for $130..00 each, but the offset will only give you a small amount-about 1/2 degree. As Jim mentioned, you would be better off milling a small amount from the factory shaft. You can can run zero camber with no problem.




Gerry

 

[UK Racer]

Alignment tips

It seems like alignment shops only want to use factory specs when setting up a front end and they seem to place more importance on getting the camber right then, if there's any adjustment room left they'll give you some caster. I'm no expert but I know one thing for sure,,, I'd rather drive a car that had a few degrees of positive caster and a bit too much negative camber. Yes, the insides of the tires would wear a little but at least It would track straight and have good road feel. By the way, the factory setting for these Chevy's calls for very little caster. This makes them easier to steer but also reduces the nice centered feel that more caster gives.

Just to say that what Jim says is good advice.
My day job is designing suspensions and my weekends are spent trying to go round tracks as fast as I can and I would agree that a bit more caster is normally a good thing for stability and feel (at the expense of a little extra weight). As for negative camber, the main down-side of a bit more than stock is some extra tyre wear which considering the low mileage most of our cars do isn't really an issue. You'll only get into real trouble at the point where the amount of negative camber begins to look wrong by eye.
Probably the most important thing is to try and get left and right side even for castor and camber to avoid the car pulling.
Adam

 

[bjburnout]

Offset Control arms

Jim is right, alignment shops used to offer off set control arms.
I purchased a set from Rare Parts Inc in California for the 66 Impala
several years ago,
Their price would probably be similar to Ecklers.........bang

http://www.rareparts.com/


bj

 

[jester]

I read an article about how after a period of time the w block would bend the frame to the point that you discribe. The article said that a shop with a frame machinc could chain each side of the chassis down to the deck , put a 20 ton bottle jack in the middle with a half inch plate steel on top and bend the chassis to add camber.

 

[chevymusclecars]

Most of the A body cars have little to no shims after alignment. I put an offset shaft and new bushings in my Chevelle and it allowed plenty room for adjustment. The set you are talking about is made by MOOG.

Hope that helps.

Bill