Another Alignment Castor Question
Thread Starter
Advanced
Joined: May 2004
Posts: 80
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Another Alignment Castor Question
h everyone,
i've been trying to do my own alignement and have read the numerous threads on the forum but i have come across a dilemma.
as you can see from the photo, camber has been set. 3 shims at each end of the a-arm. i have 0°
camber.
now i have to set the castor. to add positive castor i normally have to add shims to the rear
of the a-arm in order not to change the camber. am i right? i'm running out of thread on the
a-arm bolts.
or can i take a shim of the front position to add positive castor? will the camber i set before
change in this case?
thanks
i've been trying to do my own alignement and have read the numerous threads on the forum but i have come across a dilemma.
as you can see from the photo, camber has been set. 3 shims at each end of the a-arm. i have 0°
camber.
now i have to set the castor. to add positive castor i normally have to add shims to the rear
of the a-arm in order not to change the camber. am i right? i'm running out of thread on the
a-arm bolts.
or can i take a shim of the front position to add positive castor? will the camber i set before
change in this case?
thanks
Le Mans Master
Joined: Jan 2000
Posts: 8,918
Likes: 27
From: New Hill NC
Castor is oil, caster is lean from an axis. To change caster and not disturb camber you add or subtract the same amount of shims to the front or the rear. If you add to the front, take the same out of the rear.
Last edited by wombvette; Feb 8, 2010 at 10:44 PM.
Racer
Joined: Aug 2000
Posts: 434
Likes: 3
From: Cleveland Ohio
Adjust the caster first and then the camber. Caster adjustments are done by removing or adding shims to the front or the rear studs. Once the caster is set (equal as possible on both sides) then you can work on adding equal thickness shims to both studs to adjust the camber. After each change you make, drive the car to settle the suspension and recheck before moving on. Check out the VetteBrakes web site for goby alignment specs.
Le Mans Master
Joined: Jan 2000
Posts: 8,918
Likes: 27
From: New Hill NC
Drifting
Joined: Nov 2007
Posts: 1,701
Likes: 272
From: New York
I ran across the same issue with my 69. I had so many shims, you could not get the bolt on. But I Time Trial the car and ran more camber an a street driven car might.
As I see it, you have two solutions.
1) Bang out the Corvette stud and replace it with longer studs. A friend did this and used heavy duty racing wheel studs.
2) I went with Guldstrand Steel offset upper control arm bushings. They are drilled eccentricly so major adjustments can be made by turning the bushings and fine adjustments with a minimum of shims.
http://www.guldstrand.com/scripts/pr...p?idproduct=94
As I see it, you have two solutions.
1) Bang out the Corvette stud and replace it with longer studs. A friend did this and used heavy duty racing wheel studs.
2) I went with Guldstrand Steel offset upper control arm bushings. They are drilled eccentricly so major adjustments can be made by turning the bushings and fine adjustments with a minimum of shims.
http://www.guldstrand.com/scripts/pr...p?idproduct=94
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Racer
Joined: Mar 2006
Posts: 493
Likes: 2
From: Dunellen New Jersey
they also make an offset shaft.uses the stock bushings.Set the camber first.once thats set,move shims from front to back or visa versa.the camber will stay the same or very close to it.Once the car drives straight with the desired castor,check the camber again.castor has the most effect of pull to one side or the other.amber can also make the car pull but not as much.Then set the toe and center the steering wheel.
Le Mans Master
Joined: Jan 2000
Posts: 8,918
Likes: 27
From: New Hill NC
they also make an offset shaft.uses the stock bushings.Set the camber first.once thats set,move shims from front to back or visa versa.the camber will stay the same or very close to it.Once the car drives straight with the desired castor,check the camber again.castor has the most effect of pull to one side or the other.amber can also make the car pull but not as much.Then set the toe and center the steering wheel.
Thread Starter
Advanced
Joined: May 2004
Posts: 80
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caster
thanks guys. i'm beginning to understand the rudiments of vette alignement.
now i can set up caster with my primitive tools--level and ruler, a little bit of trigonometry amd shims.
guldstrand has everything suspension item i'am looking for.
thanks guys. i'm beginning to understand the rudiments of vette alignement.
now i can set up caster with my primitive tools--level and ruler, a little bit of trigonometry amd shims.
guldstrand has everything suspension item i'am looking for.
Last edited by wolflt1; Feb 11, 2010 at 03:38 AM.
Thread Starter
Advanced
Joined: May 2004
Posts: 80
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caster
hi again,
well, today i did some mesuring with my primitive tools and have the following approximative results.
LEFT WHEEL:
with the left wheel turned all the way towasrds the right--right turn
-.4° (-camber)
with the left wheel turned all the way to the left--left turn
+1° (+camber)
RIGHT WHEEL
with the right wheel turned all the way to the left--left turn
-.4° (-camber)
with the right wheel turned all the way to the right--right turn
+1.25° (+camber)
now the question what kind of caster do i have on each wheel positive or negative?
thanks for the help
well, today i did some mesuring with my primitive tools and have the following approximative results.
LEFT WHEEL:
with the left wheel turned all the way towasrds the right--right turn
-.4° (-camber)
with the left wheel turned all the way to the left--left turn
+1° (+camber)
RIGHT WHEEL
with the right wheel turned all the way to the left--left turn
-.4° (-camber)
with the right wheel turned all the way to the right--right turn
+1.25° (+camber)
now the question what kind of caster do i have on each wheel positive or negative?
thanks for the help
Intermediate
Joined: Feb 2010
Posts: 36
Likes: 0
My understanding is to steer the car +20 deg, take camber reading, steer -20 deg and take camber reading. Subtract the numbers and multiply by 1.5. This is your caster in degrees.
My car: about .5 deg positive at +20, about 2.25 deg positive at -20 deg. So my caster was (2.25-0.5)*1.5 = 2.626 deg. (my car had an major positive camber and a lot of toe in - the caster value was the only number even remotely close to the correct setting).
there is a hot rod article where i got this method from.
My car: about .5 deg positive at +20, about 2.25 deg positive at -20 deg. So my caster was (2.25-0.5)*1.5 = 2.626 deg. (my car had an major positive camber and a lot of toe in - the caster value was the only number even remotely close to the correct setting).
there is a hot rod article where i got this method from.
