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Caster alignment

To: tigers@Autox.Team.Net
Subject: Caster alignment
From: Anita Barrett <anitabrt@mindspring.com>
Date: Thu, 28 Aug 1997 20:48:53 -0400
At 10:07 PM 8/27/97 -0700, you wrote:
>>Subject: Pull to the Right.
>>Author:  Anita Barrett <anitabrt@mindspring.com> at INTERNET
>>Date:    8/26/97 3:45 PM     
>>Help!
>
>>The @3$!%^&#@ Tiger pulled to the right on braking. 
>>Jim Barrett Tiger 351C and others
>
>        Jim,
>
> Guess  I'd try moving as many components from the right  to the left as
>possible to determine if it's a component problem or geometry.  Might even
>make a couple of custom brake lines to switch calipers.  Last chance is to
>monitor the pressure in the lines at both calipers during braking.  It
>sounds like you have a stuck piston in one caliper which would essentially
>reduce the efficiency by about 50%.  That's one of the factors you live
>with when you have cylinders on both sides of the disc.  
>
>Tom Hall
>
>
Tom,
        I think I have isolated the problem.  First the steel brake line
going to the left was smashed by the Tire store man. When I replaced the line
the pull decreased a lot.  Second is my fault completely.  Apparently when
I replaced the A arm bushings I got the alignment shims mixed up.  Tonight
I turned the tires 22 1/2 Degrees to the left and then to the right.
I measured 2 1/2 degrees of camber on the right and 4 1/2 degrees on the
left.  This indicates to me that the right caster is 4X2.5= 10 and 
4X 4.5= 18 degrees of caster on the left.  I had noticed the caster adjusting
 shims on the left seemed to be quite extreame.  Now I know they are
way wrong.  Will redo the caster this weekend and I bet it solves the
problem.  Several Tiger people suggested Caster as the problem.  They
should have a cold one on me.
        I hope I am calculating correctly on caster.  My theory is that,
(assuming zero camber to start), if one could turn the spindle 90 degrees
then the "camber" would be the caster angle.  Therefore if I turn the
spindle 22 1/2 degrees the camber angle would be 1/4 of the caster.
That is why I did the 4x calculation.
        I have a very expensive alignment set.  It consists of a 
gravity protractor, A streight flat board that goes from one side of the wheel
to the other.  A hunk of 3/4" plywood 3 to 4 feet long and about a foot high.
a tape measure , protractor, square, pencil and a hunk of cardboard.
I use the streight board and the gravity protractor to measure camber angle.
I use a regular protractor to mark the cardboard so I can make a 22 1/2
degree triangle.  I use the plywood slapped up against the tire to 
allow me to mark the driveway with a line parallel to the tire.
I turn the steering wheel until the cardboard triangle fits between the 
previously marked line and the new line formed by the plywood up against
the tire.  At that point I measure the "camber" which is 1/4 the caster.
        The tape measure is to do toe alignment measurments along with 
a carpenters square placed vertically in front and back of the tire
in the same tread pattern slots.  Both sides are marked on the driveway
and then I measure across the car between the two rear marks and the two
front marks.  The difference is the toe measurment.  Usually set for
1/8" in.  Can't get resolution much better than this as the tie rod
ends must make full turns to line up with the steering arms.

Now if I just had a set of turn tables and a laser alignment tool...
Jim Barrett Tiger II 351C and others


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