Control/Trailing Arm Shims
#1
Instructor
Thread Starter
Control/Trailing Arm Shims
One question... when my body off is finished and I limp the Vette (slowly!) to a frame shop for a full alignment, are the shims on the trailing arms and control arms something they will be adjusting?
I am curious because I preserved the original thicknesses from dis-assembly and matched them as best I could with the new shims. I did this for both the trailing arm shims inside the frame rails near the rear, as well as the upper A-Arm shims on the 2 mounting bolts. I am very concerned with making sure that the alignment shop will do everything that is necessary to allow me to safely go 100+ MPH.
I am curious because I preserved the original thicknesses from dis-assembly and matched them as best I could with the new shims. I did this for both the trailing arm shims inside the frame rails near the rear, as well as the upper A-Arm shims on the 2 mounting bolts. I am very concerned with making sure that the alignment shop will do everything that is necessary to allow me to safely go 100+ MPH.
#3
Melting Slicks
You should be okay as long as you don't mix up the shims. You can easily double-check your work with string, a level and a tape measure to get you to the alignment shop safely.
#5
Race Director
If you replaced the trailing arm bushings and re-staked them in correctly...and filed the washers flat. The odds that if you re-installed the shims just like how the factory installed....expecting them to not be moves for a perfect alignment is highly unlikely...and the alignment shop will move them from side to side to set the toe...which is no big deal as long as the training arm can slide on the pivot bolt....which it should if you had them out and cleaned and lubed up things. Do not worry about it. The main thing is to make sure you give the alignment shop a good variety of thicknesses of shims so they can correctly set the toe. This is why replacing the shims with a new set...or like many "original guys" who want the shims that will rust...come buy and get shims that they need to get the alignment correct. I have seen many Corvettes that I have restored and repaired that have many 1/4" thick ones and very few thins ones due to they are original and it is what GM use do align the car from the factory.
AS for your upper A-arm shims. the main thing you need to be aware of is the amount of shims. The one thing you do not want have happen is that when the alignment is done...you go out and look at these four mounting points of the upper A-arms and there is either NO shims...or the shims are very thin. You will have a problem in the future....where you will NOT be able to align the front end due to cradle collapse....which is inherent. And it would be a good time to have the cradle stretched back out (apart) so you have a good thickness of shims at each of the four locations. which in turn will give you years, and years of alignment capabilities due to every year...the cradle will collapse....thus causing the two upper control arms to come closer together...and in order to get them back out for camber/caster adjustments....you have to take out shims to bring the upper A -arms back out...and then ....in time....the cradle will collapse so much....that all of the shims are taken out....and you can not adjust anything any longer....thus requiring the cradle to be stretched and the upper A-arms pulled away from each other and at the same time...applying pressure at the bottom of the engine cradle area.
I do at least 3 a year due to not having any shims at all at the upper A-arm mount area...or maybe a shim or two .
DUB
AS for your upper A-arm shims. the main thing you need to be aware of is the amount of shims. The one thing you do not want have happen is that when the alignment is done...you go out and look at these four mounting points of the upper A-arms and there is either NO shims...or the shims are very thin. You will have a problem in the future....where you will NOT be able to align the front end due to cradle collapse....which is inherent. And it would be a good time to have the cradle stretched back out (apart) so you have a good thickness of shims at each of the four locations. which in turn will give you years, and years of alignment capabilities due to every year...the cradle will collapse....thus causing the two upper control arms to come closer together...and in order to get them back out for camber/caster adjustments....you have to take out shims to bring the upper A -arms back out...and then ....in time....the cradle will collapse so much....that all of the shims are taken out....and you can not adjust anything any longer....thus requiring the cradle to be stretched and the upper A-arms pulled away from each other and at the same time...applying pressure at the bottom of the engine cradle area.
I do at least 3 a year due to not having any shims at all at the upper A-arm mount area...or maybe a shim or two .
DUB
#6
Le Mans Master
You got some stainless shims on hand? The alignment shop likely won't have shims unless they do C3's regularly.
I did same a you when I replaced my bushings. The alignment guy said it was pretty close and could have run where I put them without any real issues in the short run.
I did same a you when I replaced my bushings. The alignment guy said it was pretty close and could have run where I put them without any real issues in the short run.
#7
Instructor
Thread Starter
Thank you all for the detailed advice.
Some more info - I have 2 rebuilt trailing arms in the back and the pockets were thoroughly cleaned and painted. I have extra stainless trailing arm shims and just have the cotter pin pushed through but not bent on the ends yet.
The shop I have planned is a local frame and axle place that specializes in frame straightening and alignment but I don't know how many C3 customers they get coming through the doors... hopefully they can handle it.
DUB, On the front I have a stainless set of upper control arm shims, and am going to match the thickness of what was on the car... but would it be better to add a few more shims for adjustablility?
Some more info - I have 2 rebuilt trailing arms in the back and the pockets were thoroughly cleaned and painted. I have extra stainless trailing arm shims and just have the cotter pin pushed through but not bent on the ends yet.
The shop I have planned is a local frame and axle place that specializes in frame straightening and alignment but I don't know how many C3 customers they get coming through the doors... hopefully they can handle it.
DUB, On the front I have a stainless set of upper control arm shims, and am going to match the thickness of what was on the car... but would it be better to add a few more shims for adjustablility?
#8
Melting Slicks
talk to some local corvette clubs, ask where they get their cars done at, then call and talk to the person doing the work, ask how many c-3 they have done, look at the shop & it's equipment, ask them what spec's they are going to use when doing the work. In other words don't just go anywhere, ask around!!
If you were going to have surgery, you would ask questions wouldn't you???
If you were going to have surgery, you would ask questions wouldn't you???
#9
Melting Slicks
If you haven't experienced a Corvette at 100+mph, you might as well sell yours and get a Prius!
Raider74, whatever shop you bring it to, just put your extra trailing arm shims in a baggie and leave them with the car, making sure they know they have them. Do the same with the front shims if you have extras.
Raider74, whatever shop you bring it to, just put your extra trailing arm shims in a baggie and leave them with the car, making sure they know they have them. Do the same with the front shims if you have extras.
#10
Le Mans Master
Member Since: Jul 2006
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i've worked in an er, and i've seen the results of high speed crashes, and it's not nice. if you want to go 100+mph, install rollbars and get on a track. i don't want you to crash into me or my grandkids.
#11
Race Director
For what it is worth...I personally do not care of you drive 100mph+. All I do care about is that if you want to kill yourself ...go ahead and drive that fast...just do not do it where you can possibly have some failure/breakage in parts and hurt innocent people...that is where I DO have a problem. I do not work in an ER (obviously)...but I have seen the aftermath...and it is not pretty...that is for sure.
DRIVE SAFELY!!!!!!!
DUB
#12
Melting Slicks
Never said to do it on the street. Been to the track plenty of times to get that 100mph thrill. I guess I don't understand why you're assuming the OP means he's going to do this on the street.
#13
Instructor
Thread Starter
This has gotten a little off topic and there are some assumptions being made,
well, let me throw my $0.000002c in:
I don't need the shock value of dismembered high speed crash bodies to make me appreciate human life. That respect comes naturally for me. I too have seen the aftermath. I have also saved human lives. Most of the accidents you may have witnessed were likely either drunkards, criminals, or inexperienced joyrider drivers in the seat of a powerful machine... speeding on a busy highway or inner city where an accident is bound to happen. Perhaps they stole it and have never been in something with 500+ hp. Perhaps it is daddies... there is a reason they crashed though. Our locations differ greatly,
There are great tracks out here in Colorado, I have had the privilege of driving them many times. Due to personal connections and previous employment I have enjoyed a fair amount of machines at 100+ MPH, both on and off the track. (Corvette C5 Zo6, Audi R8, Stage 2 Subaru STI, Porsche 911, Z28 Camaro, C4s, C3s, etc.)
In a state that could swallow up North Carolina twice over... with half the population... the tracks aren't always a necessity.
There are long forgotten abandoned strips of nameless asphalt streaming through amber waves of grain...
There are countless miles of unknown curves trickling through purple mountains majesty in fractal patterns that beg for exploration...
You could drive for hours and not see a single soul. This is the crown of the west, and for now, it is still 90% wild.
I don't want to hit anyone's grand-kids, but I am honestly more worried about someones grand-kids hitting me. The average driver of today, and the standards of driving and testing, have come down a long way. The infrastructure is overtaxed with hordes of impatient, angry, selfish drivers with obnoxious stereos, GPS to rely on for direction, texting, etc.
A decade of driving, and not a single citation or accident speaks for itself on my behalf. I had a dog run out in front of me in my stingray and freeze while going 40 on a 40mph city road... I drifted around the sucker while looking it in the eyes. I hope it learned something. I have never even hit a squirrel.
How many of us have seen people put a 12" lift on their truck, skid plates, reinforced frames, snorkels, 30+" tires, etc. etc.... and it NEVER sees the dirt, and lives a sad life as a ridiculous status-symbol-trailer-pavement-princess?
Those machines are meant to span gaps, climb hills, fly over obstacles, fly through the air...
Perhaps you do not and will not ever agree with me, but there are always others that do. The world is changing and as the population grows exorbitantly these days will drift into legend:
The American Corvette is an iconic machine that embodies American freedom, and it is meant to go fast- in moderation. To not do such is putting the lion in a zoo, the eagle in a cage.
I will not.
well, let me throw my $0.000002c in:
I don't need the shock value of dismembered high speed crash bodies to make me appreciate human life. That respect comes naturally for me. I too have seen the aftermath. I have also saved human lives. Most of the accidents you may have witnessed were likely either drunkards, criminals, or inexperienced joyrider drivers in the seat of a powerful machine... speeding on a busy highway or inner city where an accident is bound to happen. Perhaps they stole it and have never been in something with 500+ hp. Perhaps it is daddies... there is a reason they crashed though. Our locations differ greatly,
There are great tracks out here in Colorado, I have had the privilege of driving them many times. Due to personal connections and previous employment I have enjoyed a fair amount of machines at 100+ MPH, both on and off the track. (Corvette C5 Zo6, Audi R8, Stage 2 Subaru STI, Porsche 911, Z28 Camaro, C4s, C3s, etc.)
In a state that could swallow up North Carolina twice over... with half the population... the tracks aren't always a necessity.
There are long forgotten abandoned strips of nameless asphalt streaming through amber waves of grain...
There are countless miles of unknown curves trickling through purple mountains majesty in fractal patterns that beg for exploration...
You could drive for hours and not see a single soul. This is the crown of the west, and for now, it is still 90% wild.
I don't want to hit anyone's grand-kids, but I am honestly more worried about someones grand-kids hitting me. The average driver of today, and the standards of driving and testing, have come down a long way. The infrastructure is overtaxed with hordes of impatient, angry, selfish drivers with obnoxious stereos, GPS to rely on for direction, texting, etc.
A decade of driving, and not a single citation or accident speaks for itself on my behalf. I had a dog run out in front of me in my stingray and freeze while going 40 on a 40mph city road... I drifted around the sucker while looking it in the eyes. I hope it learned something. I have never even hit a squirrel.
How many of us have seen people put a 12" lift on their truck, skid plates, reinforced frames, snorkels, 30+" tires, etc. etc.... and it NEVER sees the dirt, and lives a sad life as a ridiculous status-symbol-trailer-pavement-princess?
Those machines are meant to span gaps, climb hills, fly over obstacles, fly through the air...
Perhaps you do not and will not ever agree with me, but there are always others that do. The world is changing and as the population grows exorbitantly these days will drift into legend:
The American Corvette is an iconic machine that embodies American freedom, and it is meant to go fast- in moderation. To not do such is putting the lion in a zoo, the eagle in a cage.
I will not.
Last edited by Raider74; 01-16-2014 at 11:48 AM.
#16
Race Director
Seems like I great place to have fun in your Corvette...that is for sure. No areas around me like that. Roads yes...lack of people...no.
BUT...I also have to state that with your comment being an "open-ended" comment about going 100+mph. I erred on the side of caution due to you going 100+ could have been taken several ways....safely on a track, on the roads you stated you have around you...and busy city/rural streets/roads. In most cases...when high MPH speeds are written in a post...the person usually remarks that it is on a track of some type. So my assumption was warranted but incorrect. So until you clarified your statement and responded to the comments about the speed...like you did quite well I might add....many of us do care about those people who own and drive Corvettes (along with other cars)...and I, for myself...do not want anything bad to happen to you...and I do not even know you. It is a HUMAN thing. Did not mean to make you feel or think that I thought you were some inconsiderate fool.
DUB
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donevo (03-06-2022)
#17
Instructor
Thread Starter
I was attempting to be humorous by leaving the speed comment open-ended and now realize how that could affect others reading it in ways I had not anticipated. Sorry about that, and I understand the perspective you and jnb are coming from and how it can be very serious.
I would never risk endangering the life of someone outside the car, my passenger, myself, or my Vette!
It makes me appreciate even more the great community here on the forum and the great respect and care that we all have for these vehicles, and those who own, drive, and care for them.
I always appreciate the access to knowledge of those who have "been there/ done that," but the HUMAN aspect I have seen today reminds me that this forum is so much more than a technical one!
3 cheers for Corvette forum!
I would never risk endangering the life of someone outside the car, my passenger, myself, or my Vette!
It makes me appreciate even more the great community here on the forum and the great respect and care that we all have for these vehicles, and those who own, drive, and care for them.
I always appreciate the access to knowledge of those who have "been there/ done that," but the HUMAN aspect I have seen today reminds me that this forum is so much more than a technical one!
3 cheers for Corvette forum!
#19
Race Director
Raider74,
You have a good soul....and after your explanation....I know you have common sense and integrity. Like my Dad always would tell me..."There is a time and place for everything". And I would honestly have to admit...that if I had the environment that you have....I could seriously have some fun in my "driving therapy" after a hard week of repairs and business activities. Man...would I ever. But...also with that written...I also know that I could reach into a barrel of rose pedals and pull out poison ivy darn near every time. So conditions would have to be literally almost perfect.
For what it is worth...and I have found that this works best for me...is that I also do not install the cotter pin in the trailing arm bolt....BUT...I do torque it to correct torque so the base line reading can be found....which is also dependent on how tight I get the shim pack to go in. I do not like to beat the heck out of the shims to get them to fill in the gap. And I also do not want the shims to be too loose either. It is a fine line. Regardless of the method used....getting the rear toe set is always a time consuming process....which is also dependent on how precise you want to set it.
DUB
You have a good soul....and after your explanation....I know you have common sense and integrity. Like my Dad always would tell me..."There is a time and place for everything". And I would honestly have to admit...that if I had the environment that you have....I could seriously have some fun in my "driving therapy" after a hard week of repairs and business activities. Man...would I ever. But...also with that written...I also know that I could reach into a barrel of rose pedals and pull out poison ivy darn near every time. So conditions would have to be literally almost perfect.
For what it is worth...and I have found that this works best for me...is that I also do not install the cotter pin in the trailing arm bolt....BUT...I do torque it to correct torque so the base line reading can be found....which is also dependent on how tight I get the shim pack to go in. I do not like to beat the heck out of the shims to get them to fill in the gap. And I also do not want the shims to be too loose either. It is a fine line. Regardless of the method used....getting the rear toe set is always a time consuming process....which is also dependent on how precise you want to set it.
DUB