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E36 Camber Bolts and Wheel Alignments
- Subject: E36 Camber Bolts and Wheel Alignments
- From: JKEROUAC@xxxxxxxxxxxxx
- Date: Tue, 03 Dec 2002 03:15:30 -0500
re: E36 Camber Bolts and Alignment:
Mine have not shifted after 50k+ miles. In my
original posting I suggested using a torque wrench and
red loctite when installing them. Less astute
mechanics fail to use a torque wrench on critical
assembly areas, thus suffer long term loosening and or
failures on high stress connections.
The bolts allow at least 2mm of inward movement
at the top of the hub assembly. This radius is longer
than the radius from the axle centerline to the lower
two mounting bolts. Thus the effective camber
deflection increase is greater than by shimming the
lower bolts.
Also is the matter of changing the scrub radius,
another angle in front end geometry. Its not just
getting the camber, its how you get it. That's why
BMW specifies the horizontal upper bolt rather than
washers on the lower bolts.
Algignments are needed after any front end work.
Whether you use some $$ adjustable upper mount or a 1$
bolt, you still need to get on an alignment rack to
see what you're doing and get final adjustments.
The most expensive alignment rack use I had was
$210. at a ritzy Porsche/BMW/exotic place by the
Jersey shore. For my money I got exact toe and camber
settings on both sides on the rear, and indexes marked
on the front tie rods for several different toe in
settings. Typical high end specialty shops might
charge for actual time, not book, and do whatever you
want.
Remember when choosing an alignment shop, its not
just the alignment rack they have, its the alignment
operator who has to know how to use it right.
Otherwise you can get an alignment printout for
your car that looks great on paper but has no basis in
reality to the real alignment they put on your car,
simply because of improperly setting your car car up
on the rack, before they adjusted anything.
Factory specs have a _w_ide range so that any car
off the assembly line will be in spec, and also
sufficiently toed in at both front and rear to avoid
any driveability issue. This is like out of the box
jettings on Weber carbs. Box stock jetting will
definitely run in a range of engine setups, but run
extremely well in few.
Still, even from the factory you never know what
you get. One BMW I bought felt like it plowed like a
pig in the front end. Decidely far from what the
suspension I paid for should behave like. Of course
the dealer swore it was to spec, but declared the
mechanic threw out the printout. Toed all the way to
the inner side of spec itself will force bad
unpleasurable understeer. This car was much worse.
It also seemed the front of the car was too high.
I got the factory to send down someone, and guess
what? The front toe was .17 in on both sides, though
the spec was .17 toe in total. So the factory's
intent for toe in was to set it to the maximum toe in
(with worst handling) that their specs allow. How
many others have bought a BMW and thought the handling
was too tight and rough in the front end, where it was
really just a bad alignment at the factory?
Also, the BMW guy measured front suspension
height and agreed it was an inch higher than spec,
just as I had measured on others of the same model at
other dealers.
The caster and camber were both well under what
the suspension should have had. There was 1.5 degree
variation in cross caster, too. Can you spell wheel
shimmy at speed? Yep.
BMW and I agreed on sufficient remedies. No this
was not my current //M3. But I'm posting this to
describe how far off factory stock alignments
themselves can be from their specs, which are already
a wide range of tolerance so that almost any car off
the line can be considered "within specs" while
being "within specs" means very little as to whether
the suspension is really dialed in or not.
How many of you know exactly what numbers you get
when you have your car aligned? How many look at the
alignment printout to see if those numbers make sense
for the type of driving you do or road feel and
steering response you prefer.
Next time specify the exact numbers you want the
alignment set to. If the shop hesitates, that's not
the kind of shop to align your BMW anyway.
What alignment numbers do some of you set your
cars to, for what types of driving?
Off to check my thrust angle, (b:'
'jk
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