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-   -   Negative camber question (http://www.hotrodders.com/forum/negative-camber-question-180393.html)

impalaman63 07-02-2010 09:00 AM

Negative camber question
 
I have a 1963 Impala with negative camber (both tires on top tilt in)
Is this because the springs are getting old and the car is starting to sag?
Can I correct this with shims on the A arm?
I know I should replace the whole front end, but for now, I need a quick fix.
Also, if I put shims in, do I put equal # of shims on each bolt?
(photo not my frame)
http://i67.photobucket.com/albums/h2.../negcamber.jpg

aosborn 07-02-2010 09:23 AM

The crossmembers will sag over time resulting in negative camber. Yes, it can be corrected with shims to a point. If you run out of room on the studs for more shims, you will need to install offset upper inner control arm shafts. What you didn't mention is how much negative camber you have. If it is 5/8 degree or less, I would leave it as is.

To adjust camber without affecting caster, add equal amounts of shims to both bolts.

Andy

impalaman63 07-02-2010 10:07 AM

Got the nuts loose, but can't get the shims in.
Each wheel tilts in about 1/2" at the top compared to the bottom.
How would I get the shims in ?
Do I need to take pressure off the A arm some how?
Tires starting to show a slight wear on the inside edge both wheels.

aosborn 07-02-2010 11:10 AM

Jack up the car on the crossmember to take the pressure off the upper control arm. If you can get to the point where the top of the tire is tilted in about 1/8" you will be in the ball park for camber.

Andy

ericnova72 07-02-2010 02:19 PM

Adding shims will make your camber situation worse, you need to remove shims as you have to move the top of the spindle outward to remove negative camber. The offset upper A-arm shaft is frequently needed to accomplish this as usually you will not get enough camber removed before you run out of shims to remove.

Bryan59EC 07-02-2010 03:18 PM

Quote:

Originally Posted by ericnova72
Adding shims will make your camber situation worse, you need to remove shims as you have to move the top of the spindle outward to remove negative camber. The offset upper A-arm shaft is frequently needed to accomplish this as usually you will not get enough camber removed before you run out of shims to remove.

X2

Each 1/16" shim is worth 1/4 degree-----so you would have to remove 1/4" worth of shims both front and rear, to get an additional degree of camber.

Not likely to happen 'cause you probably have only a couple of paper thin shims in there anyway.

This is a common issue on the X-Frame cars from 58-64
A good frame shop should be able to push/pull it straight again.
(block the K-member and pull the the frame rails down--this rotates the top of the frame out)

Best bet would be to get he offset upper shafts.

impalaman63 07-03-2010 09:09 AM

So the best I can do is take 1 shim out all the way around.
(see photo for the # of shims I have)
http://i67.photobucket.com/albums/h2...aman63/1FT.jpg

redsdad 07-03-2010 07:17 PM

I would remove 1 from each side in the rear and two from each side in the front. But then I like lots of positive caster.

Bryan59EC 07-03-2010 09:36 PM

Quote:

Originally Posted by redsdad
I would remove 1 from each side in the rear and two from each side in the front. But then I like lots of positive caster.

This would DECREASE positive caster

redsdad 07-03-2010 10:52 PM

Quote:

Originally Posted by Bryan59EC
This would DECREASE positive caster

I have to disagree. If you remove more shims from the front than the rear, that would move the upper ball joint rearward moving the caster in the positive direction.

impalaman63 07-04-2010 07:03 AM

Why would I have 4 shims on 1 side (front bolt) and only 2 shims on the other side (FT. bolt)? Should all shims be the same on each side?

Bryan59EC 07-04-2010 07:36 AM

Quote:

Originally Posted by redsdad
I have to disagree. If you remove more shims from the front than the rear, that would move the upper ball joint rearward moving the caster in the positive direction.

You're right----I hadda brain fart :D

Irelands child 07-04-2010 08:57 AM

Quote:

Originally Posted by impalaman63
Why would I have 4 shims on 1 side (front bolt) and only 2 shims on the other side (FT. bolt)? Should all shims be the same on each side?

Not necessarily. Manufacturing tolerances on every piece, accidents, metal twists from roads will affect the base frame assembly as well as each part.

Dave W

MARTINSR 07-04-2010 09:44 AM

Alignment of collision damaged cars is one of my "things". I have to say there is no set amount of anything on the amount of shims, the thickness of shims and the placement of shims on a 45 year old car, toss everything out the window.

You put the gauges on the car, and align it. What you end up with could be five 1/16" shims on one side and two on the other in the back and a 1/32" on the front of one side and none on the other. These shims from the factory were making up for less than perfect placement of control arm mounting points. Today, after 45 years of hitting pot holes and frame sag, it is anyones guess what you will come up with, and it doesn't matter one bit, as long as the friggin wheels are where they need to be! A TINY bend in a control arm, one that you would NEVER SEE looking at it could send you off a mile. That is what the shims are for.

There is no way you can set anything without having ALL the weight in the car, the motor, the body, all the way to the front bumper.

If you are looking at your negative camber now you have no springs in it and the frame is sitting below ride height so OF COURSE you will have negative camber. Look at the upper control arms and how they are leaning? At proper ride height they are near level. The further from level they are the "shorter" they are. Meaning that the ball joint comes in towards the frame as the control arm arcs up or down. This isn't as pronounced on this car as a newer one as this car doesn't have a lot of the geomotry engineered into it as a later model car does, but you still get some negative camber on this car as the outside wheel goes up around a corner when the car leans. On a newer car this is really clear, as the car goes around a corner and the body leans, the outside tire going up into the body, right? Well, when this happens the top of the wheel goes in creating MORE negative camber giving the tire more "bite". Stand with your legs straight down, then lean your body to one side, if you put your foot out further away from the other one you can lean more, right? The negative camber being increased does this. So it is designed into your suspension to do this, the lower you have it the more negative camber. By the way, this is what the "long spindle" modification does for you. On a first gen Camaro this is one of the first improvements you make if you want to make it handle better. You put a longer spindle in it, this raises the upper control arm which in turn gives you a "head start" on the negative camber needed in the corner. Once the car leans that upper ball joint moves in quick brings the top of the tire in giving it more bite on the corner.


Forget about it until you get it up at right height. There is NOTHING you can do with your alignment with the car down like that. EVERY adjustable point, camber, caster, and toe will ALL be changed when the car is raised up.

As Bryan said, they also make offset upper control arm shafts for a lot of cars (don't know about yours) to correct alignment issues that shims alone can't.

Brian

Tony@AirRideTech 07-23-2010 09:25 AM

Quote:

Originally Posted by MARTINSR
Alignment of collision damaged cars is one of my "things". I have to say there is no set amount of anything on the amount of shims, the thickness of shims and the placement of shims on a 45 year old car, toss everything out the window.

You put the gauges on the car, and align it. What you end up with could be five 1/16" shims on one side and two on the other in the back and a 1/32" on the front of one side and none on the other. These shims from the factory were making up for less than perfect placement of control arm mounting points. Today, after 45 years of hitting pot holes and frame sag, it is anyones guess what you will come up with, and it doesn't matter one bit, as long as the friggin wheels are where they need to be! A TINY bend in a control arm, one that you would NEVER SEE looking at it could send you off a mile. That is what the shims are for.

There is no way you can set anything without having ALL the weight in the car, the motor, the body, all the way to the front bumper.

If you are looking at your negative camber now you have no springs in it and the frame is sitting below ride height so OF COURSE you will have negative camber. Look at the upper control arms and how they are leaning? At proper ride height they are near level. The further from level they are the "shorter" they are. Meaning that the ball joint comes in towards the frame as the control arm arcs up or down. This isn't as pronounced on this car as a newer one as this car doesn't have a lot of the geomotry engineered into it as a later model car does, but you still get some negative camber on this car as the outside wheel goes up around a corner when the car leans. On a newer car this is really clear, as the car goes around a corner and the body leans, the outside tire going up into the body, right? Well, when this happens the top of the wheel goes in creating MORE negative camber giving the tire more "bite". Stand with your legs straight down, then lean your body to one side, if you put your foot out further away from the other one you can lean more, right? The negative camber being increased does this. So it is designed into your suspension to do this, the lower you have it the more negative camber. By the way, this is what the "long spindle" modification does for you. On a first gen Camaro this is one of the first improvements you make if you want to make it handle better. You put a longer spindle in it, this raises the upper control arm which in turn gives you a "head start" on the negative camber needed in the corner. Once the car leans that upper ball joint moves in quick brings the top of the tire in giving it more bite on the corner.


Forget about it until you get it up at right height. There is NOTHING you can do with your alignment with the car down like that. EVERY adjustable point, camber, caster, and toe will ALL be changed when the car is raised up.

As Bryan said, they also make offset upper control arm shafts for a lot of cars (don't know about yours) to correct alignment issues that shims alone can't.

Brian


great post Brian....... beat me to it~! :)


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