Perhaps laymens terms are easier to grasp for some:
Caster: this is what makes the casters on your grocery
cart stay lined up and aimed in the direction the cart
is going. It is created by offsetting one kingpin
forward of the other. On a car, it makes the steering
return to center after letting the steering wheel go
after a corner (without it, you see the coroner after
the corner).
Camber: the amount the tires lean to one side (usually
set to lean in). This angle is similar to the angle
the lower half of one's legs eventually takes on when
one gets waaaay to fat to fit in their LBC. This angle
can be simulated without the weight gain and without
many years wait for you skekital system to collapse by
simply getting what we used to refer to as "racked
up".
Toe in: the pigeon toedness of your front end. The
difference in the distance between the center of the
tread on the front edge of the front tires and the
center of the tread on the rear edge of the front
tires. The reference may actually be the outer edge of
the tread, but in practice, either works. Although
this angle may also be simulated when being racked up,
it is separate and unrelated to the other angles in
the automotive world. This is the only angle that is
an easy adjustment.
Ackerman angle: ouch. I sprained my back on that one,
so we won't discuss it.
On most cars, caster and camber is not adjustable;
it's fixed by replacing all the worn and bent parts
that caused it to be wrong. Or by removing the poorly
designed modifications that mucked it up. The toe in
can and should be checked/adjusted after doing your
own front end work. Use the Grannville King method:
Make the tool:
Cut a 2 X 2 a foot wider the the track width of the
car. Drive a long nail through one end of the 2 X 2.
Measure the approximate distance between the center of
the treads. Drive another long nail through the other
end of the 2 X 2 at a distance, from the first nail,
equal to what you just measured.
Mark the tread:
Jack up the front end and give one tire a good spin.
Mark approximate center of the treat by gently
pressing a sharp nail against the tread while the tire
spins, allowing the nail to score the rubber all the
way around.
Get ready:
Drop the front end down and drive at least ten feet
forward with the tires pointed straight forward (if
you are in the garage, you may want to back up before
driving forward).
Get set:
have some cheap labor hold the nail on the mark on the
front of one tire (preferably at a height equal to the
center of the wheel bearing). You hold the other nail
up near the other mark on the other tire, and bend the
nail, so it lines up with the mark exactly. Move the
stick around to the back side of the tire and repeat
the measurement. For a typical 1/8 inch toe in, the
rear measurement should be 1/8 in. wider, meaning the
nail should be 1/8 inch closer to the center of the
car than the mark is.
Go:
Adjust a tie rod and repeat the measurement. As you
adjust, both front and rear marks move, so you have to
bend the nail each time.
This should get you close enough to get to the
alignment shop without eating a tire, and if your
good, they won't need to do any adjustments.
jon
=====
77 MGB "Christine" slowly, but surely healing
58 Willys CJ-3B, the Killer-B
The saddest thing in the world is watching your father turn into your son. The
hardest thing in the world is to take care of him as well as he took care of
you. Love you parents while they're still healthy. - Jon Paulsen
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