Hi Group. Well I am finally getting my alignment on the Tiger to come
into spec, which is 4 degrees pos. caster, 1/2 degree neg. camber, and
1/8" neg. toe in.
The ackerman angle is equal last time I checked, using Dale A's ackerman
kit, which includes an adapter and extensions for the parts you
purchase, which include a MG Miget R&P, MGB Steering Arms, and Alpine
tie rod ends. This is an improvement from the stock Tiger ackerman
angles which has a larger radius on the inside turning radius than the
outside. By now, you are aware that when backing up, with the wheels
turned sharply, this has been the probable cause of the lower fulcrum
pin breaking.
First a Big Thanks you to Tom Hall, Bob Palmer, John Logan, and I am
sure I missed someone, for the help in getting this portion of the car
set up.
I went from the stock 225 ppi springs, to CAT 335 ppi springs to 425 ppi
springs. The CAT springs were too tall, and I cut the springs, with an
abrasive wheel, heated the cut coil end, and ground that end so that it
would sit square.
I was not happy with it, don't ask, and purchased a 425 ppi spring, with
the recommendations of Bob Palmer. I drove Larry Wrights car with these
springs, and it is not harsh, like I expected it to be, with almost
double the spring rate.
I am waiting for Rick at SS to send the 7/8" diameter anti sway bar, as
the first one was for an early Alpine, not the Tiger, and it would not
fit. Problem is the company making the bars, is currently having
problems, and I have to wait for the new bar.
For those of you who have never done this before, it's not so bad if you
know how to tackle the issue, so here goes on what I learned.
1. First, you will need to determine what you are going to do with the
car, ie touring, autocrossing, etc, so that you can decide on the specs
for alignment.
After many emails from many people, I settled on an alignment spec of 4
degrees pos. caster, 1/2 degrees neg. camber, and 1/8" neg. toe in.
This will provide a reasonable touring car, but allow autocrossing,
while not getting so far out of spec to ruin your tires for daily
driving. This is a personal preference for many drivers, but this is
what I am going to start out with.
2. The alignment must be set up in the following sequence, caster,
camber, and toe in. There are several web sight that explain this
sequence, and what each of the 3 alignment specs are. A good one is
http://www.longacreracing.com/.
Note - I purchase a Longacre caster/camber alignment tool for
approximately $160. This includes the alignment tool itself, and an
adapter that screws onto the few threads of the spindle where the front
wheel bearing are located. If the nut holding the bearings on is good
with no rough surfaces, then you have a very stable and repeatable
platform for measuring the caster/camber.
You will need a reasonably level surface to put the 4 wheels of the car
on, but the Longacre gauge allows for a surface that is not completely level.
When you get your car aligned at your local mass merchant store, they do
not allow you to sit in the car. When you sit in the car, the caster
and camber settings change, and therefore it is more accurate if you can
have the car set up for how you will normally drive your car, with you
in it, in the situation where you want accurate alignment, ie autocrossing.
There are also very expensive turntables, that allow the front wheels to
move with the weight in the car, ie you, and when you turn the front
wheels left and right to measure the caster. You can get very accurate
measurements by using plastic garbage bags under the 2 front wheels.
This surface allows the wheels a relatively slippery surface to move on,
and while is not as good as the $400-$1,200 turntables, works very well.
When setting up the car, bounce the front up and down to settle the
alignment, after making changes with shims. Then take the car for a
short ride, come back, and check the specs again.
Set your tire pressure to specs, gas in tank at least 1/2 full, and the
normal stuff you would have in the car if you were racing/autocrossing,
but not all the junk found in a lot of cars. The extra weigh will
change the alignment of you car.
Doing your own alignment allows you to do this.
ALWAYS TORQUE THE BOLTS TO SPEC, WITHOUT FAIL. KEEP IT SAFE, AND DO NOT FORGET.
3. Setting up the caster can be accomplished in 2 ways. If the car is
really out of spec, and factory spec is 3 degrees and 50 seconds
positive caster, just about 4 degrees, such as mine was you can add
shims under the cross member, between the alum wedge spacer and the
frame rails. My caster was 1.5 degrees pos. caster on the left, and 1.5
degrees neg. caster on the right.
a. I found an alum ruler from Home Depo for $7, yes ruler, that was
1/8" thick and 2" wide, the same width as the alum spacer that goes
between the crossmember and the frame rails. I used the original alum
wedge space as a templet to find the location of the hole where the 5/8"
diameter bolt goes through the crossmember, and bolts to the frame rail.
I cut the ruler in 2" long strips for the spacer. Bonus is that you
have the measurement right on the ruler.
I used 2 spacers for a total of 1/4" at the rear of the alum spacer.
This added approximately 2 degrees pos caster to the car. It has been
suggested that you not add more than 1/4", and after looking at this
spacer, I thing that should be the limit.
BTW, I tried adding 1/4" spacer on the left, and a 3/8" spacer on the
right to correct the difference in the caster noted above. It did not
work, as I only got 2 degrees with either the 1/4" or 3/8' spacer. It
also shows that the crossmember is really stiff. As pointed out to me,
it may over time do something funny to the frame rail on the right.
b. The additional caster, or if your car is not that far out of spec,
is set up at the rear bolt on the upper a arm, by adding single shims at
this point.
This is how you do it.
Get various thickness single shims from a body shop or good auto parts
store. Use alignment shims, not body shims, as the alignment shims have
a tab with a hole in it to grab, as opposed to the body shim, without
the tab. Much easier to work with when adding or subtracting shims.
Put a jack under the front a arm, jack up the car, take off the wheel,
and use a 5/8" socket with extension to loosen the 2 upper a arm bolts.
Now jack the car up further, so that you take the tension of the spring
off of the upper a arms.
You may need a pry bar, screw driver or something to break or loosen the
a arm for the crossmember tower that it bolts onto. If everything is
clean and new, HA, you may be able to move it apart by hand. What you
want is to get enough space to add or subtract shims.
If you need to get more pos caster, add a single shim to the rear bolt,
and tighten both bolts to spec, ie 52 ft-lbs. Put the tire on, lower
the jack, bounce the car again, and check the new caster.
Sounds like a lot, but not that bad, and after adding the first shim and
checking the caster, you will get the hang of it.
Set the caster for both sides.
4. Setting the camber is next. The procedure is similar to setting the
caster on the upper a arms, but you will be using a double shim, that
goes behind both bolts, and not a single shim. Use the same general
procedure as above for caster.
Now check your camber. Then check you caster again, and it may have
changed with the camber.
Remember, you set the caster first, then camber, then check both, and if
the caster is off, change it first, then go to the camber. It may take
several tries on the first attempt, but after you get it right, changing
it to a different setting later is very easy, as you have now set up a
base line to work from.
Again drive the car for a short distance, and check the caster and
camber in that order. If it is still good, then you move onto toe.
5. Toe does not effect caster/camber, and is adjusted by the adjusters
on the end of the R&P and tie rods.
The first thing you want to do is to make sure that your steering is
centered. To do this, with the car jacked up, turn your steering wheel
to the left and right, mark each, and then cut in half to find the true
center of the R&P travel. Mark this, and if necessary, take off your
steering wheel and realign it to be in the true center of the R&P travel.
Next, using a straight edge make sure your front tires are pointing
straight ahead. You can use electrical conduit as a long straight edge,
again Home Depo, and carpenters squares, but while there are several
ways, you want to get the tires point straight ahead.
You may find that that with the tires straight ahead, the steering
wheel, that is now in the true center, is not centered. No problem.
You adjust the toe in adjustment to get the wheels pointing straight
ahead first. If the car has pos. or neg. toe, don't worry, because you
want to get everything pointing straight first.
The next and final step is now easy. Jack up the front, so that the
tire are just off the ground, and spin the tires, and using a nail or
sharp point, put a mark on the tire. Adjust the adjustment screws on
the left and right tie rod ends, to get your toe, measuring the front
and back of the tire at the same height off the ground, on the scribed
mark to get your toe.
You are now finished, and Congratulations.
Larry
PS - If if missed something, or it is incorrect, please email a
correction or comment. Thanks.
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