Does anyone know how much change in camber will occur with each shim installed?

What is the maximum number of shims that may be installed on each side?

My right front tilts at the top towards the center line of the car. Lower adjusting shaft does not correct. Printout from alignment machine indicates -2.9 deg camber with a specified desired range of -0.5 to +0.5 deg.

I do not know if there are any shims installed. I believe this car was hit in the RF at some point. Is there some what to measure the spindle support (link between the upper and lower control arms) and spindle to see if something is bent?

Car drives straight, does not pull. Old tires wore on inner to treads.

Thanks,

Bob

 

C1's don't use shims anywhere for caster/camber adjustment; that adjustment is made at the upper outer bushing, at the top of the spindle support (upright).

After you remove the grease fitting, an allen wrench is used to turn the shaft, which has an eccentric at the center; the shaft moves fore-aft to change caster, and the eccentric changes camber. You have to loosen the upper clamp bolt on the upright first.

 

JohnZ: Thanks for input. I have made the adjustments you mentioned on the upper control shaft excentric/allan screw but the problem remains.

If shims are not used on C1's, what it the purpose of those that are shown by suppliers like Corvette America no. X2167 and Eckler no. 41593. These are described as aluminum and shown going between the front cross member and frame rail.

Finally, is there some way to determine if either the support link or spindel are bent? Is there a measurement for the centerline of the spindel compared to the centerline of the support link shafts? Would this be 90 deg.?

 

Here's a couple that ARE NOT in the books. ONLY an old time, experienced front alignment shop would know this.

But first, the alum shims that are offered by the vendors are stock (replacements) for shims that were in ALL 56-62 Vette frontends, installed BETWEEN the bottom of the frame rails and the front cross member. Unfortunately, I don't have any available to take a picture for posting here. These (wedge shaped) shims are fairly easy to see if they are in your car (thick end of shim toward the rear of car). As I mentioned above, these are standard in ALL 56-62 Vettes, thus, they SHOULD be in your car. Back in the days when these cars were regularly raced, it was common for some racers to setup their frontends with TWO shims on each side to increase caster. Good for the race track, not so good for regular street driving.

Now, on to the couple of tricks I mentioned. As has already been pointed out, BOTH caster/camber for 53-62 Vettes (also 49-54 pass cars----same frontend) are adjusted by turning the upper-outer shaft with an Allen wrench through the grease fitting hole.
SOMETIMES, the adjustment cannot sufficiently increase/decrease caster/camber. With the adjustment of the upper-outer shaft, as camber is changed, the caster also changes accordingly. You MAY get the caster where you want it, but then the camber is beyond the outer (or inner) limits and vice versa. Thus, time for a trick. I have attached a picture of how regular alignment shims can (and sometimes are) installed at the front or rear of the inner-lower A-frame shaft. The picture below is on my 56. Another trick, or alignment method, was moderately common on numerous 40s-50s cars, including the 53-62 Vettes, when nothing else would bring the alignment into specs. BENDING. Yep, and if you have ever seen an alignment shop do this procedure, it's scarry as hell to watch them bend your treasured early Vette!!! There are two tools (one to bend out, one to bend in) for bending the upper portion of the spindle support (upright). This tool is affixed to the spindle support, the upper A-frame is blocked so that it can't swing, then a powerful hyd jack is placed against the tool and pressure applied until the spindle support is slightly bent. As I said, it's scarry as hell to watch--------------so I recommend you don't do it! Also, MANY years ago, this bending procedure was common, but few, DAMN FEW, alignment shops even know how to do it-------------much less have the tools!




Tom Parsons

 

Tom: I had my 62 at the shop in OKC that you had previously recommened and they are the ones who gave me the print out. They also have the tools you mentioned as a last resort to bend things. With the risk of hearing that matalic 'clink' and then not having any way to get car back on trailter to Knoxville, we did not go that route.

I have a better understanding of the shims between the cross member and frame rails. However, will the regular alignment shims at the front or rear of the inner-lower A-frame shaft you mentioned affect my condition (top of tire leans in towards center line of car)?

I will send you a private e-mail and picture.

thanks,

Bob

 

Bob,
The shims, as in the picture above, AND, depending on the condition/geometry of your frontend, can POSSIBLY make enough change in the caster that it will THEN permit adjusting the upper-outer shaft to gain (or remove) the needed amount of camber.
Is that clear as mud?

I'm old enough, and go far enough back, that I've picked up on this kind of stuff from shops/garages which have been out of business for several years.
I started out with (and it's literally still my daily driver) a 51 Chevy back in 1962, and since 49-54 pass cars have the same frontend as the early Vettes, I am now pretty familiar with all these kinds of things. These are the kinds of little things you want to do as a last resort before having any bending done. My 51 Chevy has one spindle support that was bent (MANY years ago) and everything has been just fine ever since. I watched the OLD alignment guy bend it and I about had a cow! But in 40+yrs now, no problems.


Tom Parsons

 

Any good alignment guy ( and there aren't many left- they just read red and green) can tell you if something(and what) is bent, but not with one reading off one wheel.. what are all the rest of the readings (both sides) caster begets camber, and both impact toe. Was the camber reading at 0 degrees toe? What is the SAI? and setback? What was toe prior to adjustment? Thrust angle is also good to know. Although not much can be done to adjust it, what are the rear angles?
You state the car doesn't pull, yet if the other side was in spec (a 2 degree camber difference), unless the other side had caster pulling back,or rear toe was pushing it back, that is about impossible, so you see why you need all the readings..Let me know if I can help....

 

Ride height (springs) affect alignment. How are your springs?

For example, rear springs sitting too high will reduce caster.
Front springs sitting too low wll reduce camber.

 

hi,

anybody has a picture of the tools ?
thanks.
Pascal

 

THIS^^^^. You need to get the car on an alignment rack and have the tech do a caster cut in order to get the SAI (Steering Axis Inclination angle) on each side of the car. This is a 'built in', non-adjustable angle. If the SAI is different from side to side, you have a bent steering arm or other bent part. You say the car was possibly hit, so this is the correct course of action. Once the bent part is addressed, your stock alignment cams will bring the car into spec. Trying to fix a bent part by grinding/cutting/bending other components will not cure the problem and will only cause others.

 

Hi,

i tried to put a shim ( 2 and after 5 mm) but i'm unable to get more than 0.5 degrees for the camber ....I need 1 degree more.
The steering is heavy and not very accurate . so the only solution would be to bend the spindle support ....
2 demands : 1. the spindle support is cast iron and if i'm right you can't bend this metal without warming it . I'm right ?
2. Would you like to share a picture of the tools ?

Thanks.
Pascal

 

The 53-62 spindle supports are NOT, repeat, NOT cast iron, They are forged steal.
If your caster/camber is that much out of spec, something is wrong somewhere else.
Just out of curiosity, does your car have the wedge shaped shims BETWEEN the frame and front cross member?

 

If you start bending parts you will RUIN them. And your car will drive and steer unsafely. Please read up on SAI and front end alignment angles. Again, your car needs to be put on an alignment rack, have a caster cut taken, and have the SAI angles verified. If different side to side, you have a bent part that must be replaced. I have been aligning cars professionally for the past 38 years, so take my advice ....or not. Your car.

 

Hi,

thanks for the answer.
i was just thinking to change the shim between the frame and front cross member.... but this changes the caster and not the camber.
i'm wrong ?
Pascal

 

Hi;
Thanks for the answer.
Ok; i understand : i put the car on the rack and i meet a problem with the right wheel. ( picture tomorrow ) the caster ( 1 degree +)and camber ( -0.5 degree) are not right. So the problem is on the right side .
Is it a good idea to replace first the aligment shim ?
thanks.
Pascal

 

No, your understanding is correct.

Jim

 

ok, i come back when i get the shims ! But i'm living in Europe .... so 3 weeks !
Thanks
Pascal

 

That is correct. The shims between the frame and cross member will only affect caster. BUUUUUUUUUT, once the caster is changed, THEN, there may be enough adjustment available with the upper-outer shaft to improve the camber.

 

Hi,
i'm not so optimistic !
I put a shim on the rear of the front cross ( 5 mm ! ) and i can't get the right camber ( - 1 degree. ) So i do not think that a new shim under the frame will give me the right resutt ...
you can see the rack result without any shim .... May be should i buy a new splindle support but where can i find a new one ?
Thanks
Pascal

 

Hi,
Solved !
the shim on the under the frame was ok ... so i put the spindle support under a hyd jack , get 2 degrees more !
Thanks for the help !