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A lot of us would rather do it ourselves than
take our Corvette to an alignment shop that hasn’t
seen a C2-C3 Corvette in 20 years. I have used
this method for years, and it will put your car
on the money.
All
you need to align the rear end of your 63-82 Corvette
is an hour or so, a short level, a pair of 2’
by 4 x 4 wood blocks, two 3-foot aluminum straight
edges, a framing square, some string, a measuring
tape and a helper.
Your
car needs to be on the garage floor, with all
the trailing arm shims removed from the front
trailing arm bushings.
First
the ride height at the rear should be set. Your
car’s favorite ride height is where the
half shafts are horizontal. In this position,
the U-joints don’t have to work much at
all, but that may be too low for you. Adjust the
ride height to your favorite position by tightening
or loosening the spring bolts.
Next
is track. We have to have the toe-in equal on
both sides so the car will track straight down
the road. Position the rear wheels as close to
straight as possible. This is easy even with weight
on the car, as you can use the trailing arm as
a big lever to pull or push the front of each
wheel in or out.
Make
sure the front wheels are straight. Have your
helper hold one end of an 8’ string on the
outside of the left rear tire behind the axle,
at the height of the axle. Pull that string taught
to the front of the car and move it in until the
string just touches the front of the rear tire
in the same position as your helper has the other
end pinned at the rear.
With
the taught string in your left hand, use your
right hand to measure the distance between the
string and the dust cover of the front spindle.
If you have rally wheels, measure to the center
of the cone.
All
we are trying to do is get a relative measurement
to which we can compare the other side. Repeat
this procedure on the right side, and go back
and adjust the tow by hand until both lines of
alignment are equal when measured relative to
the front axle reference.
At
this point your Corvette is tracking straight,
but we have not yet set the toe. We have set the
track.
To
set the toe, place the 2’ 4X4 wood blocks
on the floor outside, centered and up against
the rear tires. Place the 3-foot aluminum straight
edge on top of one of these blocks, centered on
the tire. Have your helper hold the strap tangent
to the outside of the tire. In case you are wondering,
the purpose of the block is to elevate the aluminum
straight edge above the bulge in the tire at the
floor.
Now
you go to the other side and place your block
and aluminum strap in the same relative position
and feed the end of your tape measure under the
car to your helper on the other side. Measure
the distance between the aluminum straight edges
in front of the tire and behind the tire, again
with both aluminum straight edges sitting on the
reference blocks and tangent to the outsides of
the tire.
Our
target is 1/8-inch total toe. That means the distance
between the front of the tires should be 1/8-inch
less than it is at the back of the tires. It won’t
be. You will have to torque the arms in or out
to achieve this number, but the trick is to do
it half on one side and half on the other. When
you think you are there, go back and do the string
trick again to make sure you are still tracking
straight down the road. Adjust accordingly and
repeat until it is both tracking straight and
the total tow is 1/8-inch.
When
you are there, put the spacers in and tighten
up the trailing arm bolts. Check it again just
to make sure, and then insert the cotter pins
in the trailing arm bolts and in the shim packs
and you are finished with the toe adjustment.
Last
we adjust the camber, which is the angle the rear
tire sits to the floor. The target is ¼
to ½ degree negative camber, meaning we
want the top of the tire to be tilted in just
barely, like 1/8 to 3/16 inch from vertical. You
adjust that with the strut rod cam bolts that
are located under the differential. Loosen, twist,
tighten, measure, and repeat as necessary until
you get it right. You will have to roll the car
between adjustments to allow the tire to move.
When
you are all finished, if you are into self-abuse,
you can drive the car around the block and measure
the toe again. It will go much faster this time.
Remember we need to have the toe-in right, but
we must also have the tracking equal left and
right.
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