Help: Alignment Troubles

[crstibr]

Hello ! So recently i’ve been attempting to get my E30 aligned properly as the car does not self steer back to center and appears to be ‘crab walking’ when driving in a straight line.

modifications :

Front: E36 BC Coilovers / Knuckles, GAS (FAPO) E30/36/46 angle kit, E46 Purple Tag Rack

Rear: E30 BC Coilovers, Poly trailing arm bushings , Poly subframe riser bushings, Normal Poly Diff Bushing (not raised) 5 Lug Conversion, Toe / Camber Eccentrics

Method : A combination of Toe plates and string alignment. the string is measured from axel / wheel bearing nut on each corer and adjusted so that the string is equal distance from each front and rear independently. when these numbers match, i’m confident the string is parallel to the frame.

Questions:

1) when pulling back steering rack boots, i’ve verified that rack is centered among itself (inner shaft same distance from outer rack housing on both sides) , but when i zero out the toe i am clearly seeing a difference in exposed thread on the outer tie rods. a. is this okay ? and b. why is this? is the rack not centered among the chassis? i am fairly certain that caster (lollipops) and camber(tophats) is the same on each side.

1) in the rear, i have zero toe in reference to the strings (parallel to car) but i believe the rear thrust may be off. crude measurements show a slight difference in measurement from wheel to front of rear arch. i believe this to be the cause of my ‘crab walk’ issue. is there any way to correct this?

Car has a clean title and does not appear to have pickups damaged also.

Thank you in advance !

[TobyB]

Starting from the beginning-

1) it's going to be best to find the true centerline of the chassis.
In front, that's the position equidistant from the inner ball joints,
and in back centering between the trailing arm mounts is good.
You then use a string setup to indicate the centerline from behind
the rear bumper to in front of the front. (with aluminum bumpers,
you can drill small holes in the undersides and tap them for allthread.
Then you always have center when you need it.)

Then you align the rear trailing arms so that the wheels are exactly parallel
to centerline. That's the straightforward way to get started.
Adding a half- degree of toe in might help stability under braking...
https://www.amazon.com/How-Make-Your.../dp/0912656468
is where I learnt this, the first time.

1) as to the rack, have you confirmed that you're making the same exact
number of turns to each stop? I've always gone end- to- end, counted the
turns pretty carefully, divided by 2, and rechecked my work a couple
of times. It doesn't matter so much with a rack, but back in the steering
box days, the box was only truly tight right on center.

1) as to not self- centering, if nothing in front is binding, the first thing
to look at would be caster. Depending on what you're doing, a little is always
good, and sometimes, more is better. I like the positive camber gain I get with it
on the racetrack, but dislike the heavier steering on a street car.

1) good luck!

t
b) is by no means an expert at this stuffs.