tire size BMW 328i 1994 E36 Workshop Manual

Page 250 of 759


300-2



SUSPENSION,
STEERING
AND
BRAKES-GENERAL

Steering

INTEGRATED
SYSTEMS

The
steering
linkage
connects
the
rack-and-pinion
unit
through
tie
rodsto
the
steering
arms
.
The
tie
rod
ends
allow
the
wheels
to
pivot
and
react
to
suspension
travel
.

Rear
Suspension

The
rear
axle
carrier
is
the
main
mounting
point
for
the
final

drive
housing
and
the
rear
suspension
components
.

Trailing
arms
locatethe
rear
wheels
and
anchorthe
springs,

shocks
and
stabilizer
bar
.
Driveaxies
with
constant-velocity

(CV)
joints
at
both
ends
transfer
power
from
the
differential
to

the
road
wheels
.
The
differential
is
mounted
to
the
rearaxle

carrier
through
rubber
mountsand
bushings
to
hele
isolate

drivetrain
noise
and
vibration
.

Brakes

E36
cars
areequipped
with
power
disc
brakes
with
an
inte-
gral
antilock
brakes
(ABS)
.
The
parking
brake
is
a
dual-drum

system
integrated
with
the
rear
brake
rotors
.
See
Fig
.
3
.

Power
assist
is
provided
by
a
vacuum
booster
when
the
en-

gine
is
running
.
The
brakepedal
pushrod
is
connected
directly

to
the
master
cylinder,
so
failure
of
the
vacuum
booster
does

not
normally
result
in
total
brake
failure
.

0012124



Each
disc
brakeuses
a
caliper
with
a
single
hydraulic
cylin-
Fig
.
2
.



Front
suspension
control
arm
(arrow)
.



der
.
Brake
pads
in
the
left
front
and
right
rear
contain
wear

sensors
.
When
the
padsneed
replacement,the
sensors
illu-
The
front
suspension
is
designed
with
minimum
positive



minate
a
light
on
the
dashboard
.
steering
offset
.
This
geometry
contributes
to
stability
when

traction
is
unequalfrom
side
to
side
.
Suspension
travel
is
lim-



Tires
and
Wheels
ited
by
rubber
bump
stops
.

The
three
point
mounting
of
each
L-shaped
control
arm
ere-



Tiresize
is
critica¡
to
the
proper
operatíon
of
the
E36
ABS
or

cisely
controls
the
front-to-rear
and
side-to-side
position
of
the



ABS/AST
system
.
Severa¡
different
styles
of
wheels,
in
15,16

strut,
while
the
flexibility
of
the
joints
and
mounts
alsoallows



and
17
inch
diameters,
are
available
from
an
authorized
BMW

the
movement
necessary
for
suspension
travel
.
The
control



dealer
.

arm
mounting
points
are
designed
with
anti-dive
geometry
.

The
suspension
reduces
the
normaltendency
for
the
front
of



NOTE-
the
vehicle
to
dive
under
hard
braking
.



Aftermarket
wheelsshould
be
selected
wlth
care
.
Im-
properly
fitted
wheels
can
contact
anddamage
sus

Control
arm
position
is
fixed,
with
no
adjustment
provisions



pension,
brakeorbodycomponentsandmayadversely

on
the
control
arms
for
alter¡ng
front
wheel
al
ignment
.
A
stabi-



affect
vehicle
stability
.

lizer
bar
mounted
to
both
control
arms
heles
to
reduce
body
rol¡
whencomering
.



INTEGRATED
SYSTEMS

Antilock
Brake
System
(ABS)
is
standard
on
all
E36
cars
.

The
variable-assist
power
steering
system
consists
of
an



Standard
on
some
models
and
installed
as
optional
equipment
on

engine-driven
hydraulic
pump,
a
rack-and-pinion
type
steer-



others,
is
All
Season
Traction
(AST)
.

ing
gear,
and
connecting
linkage
to
the
road
wheels
.
TheE36
utilizes
an
engine-speed
dependent
variable
effort
steering



Antilock
Brake
System
(ABS)

system
.
At
low
speeds,
maximum
power
assist
is
provided
to
ease
parking
and
city
driving
.
Athigh
speeds,
assist
is
re-



The
electronically-controlled
ABS
maintains
vehícle
stabili
duced
to
ensure
stability
.



ty
and
control
during
emergency
braking
by
preventing
wheel
lock-up
.
ABS
provides
optimum
deceleration
and
stability
dur-

Page 255 of 759


increased
power
output
and
road-handling
demands
.

The
steering
geometry
is
modified
by
changing
the
cast-

er/camber
angles
slightly
.
This
is
accomplishedby
reposition-

ing
the
upper
strut
mounting
holes
in
the
frontstrut
towers
and

through
different
front
and
rear
control
arms
.

M3
Brake
System
Improvements

"
Vented
directionalfront
rotors
:
315
mm
dia
.
x
28
mm
thick
.

"
Vented
directional
rear

rotors
:
312
mm
dia
.
x20
mm
thick
.

"
Larger
brake
pads
and
calipers
.

"
Modified
Teves
ABS
system
.

SUSPENSION,
STEERING
AND
BRAKES-GENERAL



300-
7

M3
SUSPENSION
AND
BRAKES



NOTE-

M3
brake
rotors
are
directional,
having
a
different
part

TheE36
M3
was
introduced
in
late
1994
as
a
1995
model
.



number
for
each
side
.
Rotors
with
an
odd
part
number

The
design
of
the
M3
suspension,
steering
and
brakes
is
a



go
on
the
left
while
rotors
with
en
even
part
numbergo

modification
of
existing
E36
systems
which
accommodates



on
the
right
.

M3
Front
SuspensionImprovements

"
Reinforced
spring
plates,control
arms,
control
arm
bush-

ings,
steering
arms
.

"
Recalibrated
struts,
firmer
springs
.

"
Stiffer
stabilizerbar,
larger
stabilizer
bar
bushings
.

"
Front
stabilizer
linked
to
struts
.

M3
Wheels/Tires

"
Front
wheels
1992-1998
:.....
7
.5J
x
17
in
.
light
alloy

"
Rear
wheel
1992-1997
.......
7
.5J
x17
in
.
light
alloy

"
Rear
wheel
(option)
........
.8
.5
Jx17
in
.
light
alloy

"
Front
and
rear
tire

1992-1997
.............
.
.
.
...
...
235/40
x
17
in
.

"
Front
tire
1998
only
......
...
.
.
.
...
225/45
x
17
in
.

"
Rear
tire
1998
only
.......
.
.
.
...
...
245/40
x
17
in
.

CAUTION-

In
en
emergency,
an
M3
front
wheel/tire
assembly
may
be
mounted
on
the
rearaxle
.
However
a
rear
wheel/tire
assemblymust
not
be
mounted
on
the
front
axle
.

M3
RearSuspensionImprovements

"
Reinforced
trailing
arms
.

"
Recalibrated
shock
absorbers,
firmer
springs
.



SUSPENSION
AND
STEERING

TROUBLESHOOTING

Stable
handling
and
ride
comfort
both
depend
on
the
integ-

rity
of
the
suspension
and
steering
components
.
Any
symp-

tom
of
instability
or
imprecise
road
feel
may
be
caused
by

worn
or
damaged
suspension
components
.

When
troubleshooting
suspension
and
steering
problems,

also
consider
the
condition
of
tires,
wheels,
and
their
align-

ment
.
Tire
wear
and
incorrect
inflation
pressures
can
dramati-

cally
affect
handling
.
Subtie
irregularities
in
wheel
alignment

angles
also
affect
stabílity
.
Mixing
different
types
or
sizes
of

tires,
particularly
on
the
same
axle,
can
affect
alignment
and

may
unbalancea
car's
handling
.

Table
b
lists
the
symptoms
of
common
suspension
and

steering
problems
and
their
probable
causes,
and
suggests

corrective
actions
.
Bold
type
indicates
the
repair
groups

where
applicable
test
and
repair
procedures
can
befound
.

SUSPENSION
AND
STEERING
TROUBLESHOOTING