1995 BMW M3 fig 27

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-

Wheel
brake
caliper

Electronic
control
module
Fig
.
4
.



Schematic
representation
of
ABS
.

SUSPENSION,
STEERING
ANDBRAKES-GENERAL



300-3

Fig
.
3
.



Schematic
view
ofdual
circuit
brakes
with
4-channel
ABS
.

ing
adverse
conditions
.
It
automatically
adjusts
brake
system
hydraulic
pressure
at
each
wheel
to
prevent
wheel
lock-up
.

The
system's
main
components
arethe
wheel
speed
(pulse)
sensors,
the
ABS
control
module,
and
the
hydraulic

control
unit
.
See
Fig
.
4
.

Warning
lamp

u
Master

Whee

_

l
speed



I-lydraulic



cylinder

sensor



control
unit



0012135

UNI

The
wheel
speed
sensors
continuously
send
wheel
speed
signals
to
the
control
module
.
See
Fig
.
5
.
The
control
module
compares
these
signals
to
determine,
in
fractions
of
a
second,
whether
any
of
the
wheels
areabout
to
lock
.
If
any
wheel
is
nearing
a
lock-up
condition,
the
module
signals
the
hydraulic
unit
to
maintain
or
reduce
pressure
at
the
appropriatewheel(s)
.
Pressure
is
modulated
by
electrically-operated
sole-

noid
valves
in
the
hydraulic
unit
.

Fig
.
5
.



ABS
wheelspeed
sensor
.

0006563

INTEGRATED
SYSTEMS

300-4



SUSPENSION,
STEERING
AND
BRAKES-GENERAL

Three-channel
ABS
ís
used
on
al[
E36
cars
equipped
with



Al¡
Season
Traction
(AST)
standard
ABS
.
Each
front
wheelhas
a
separate
solenoid

valve
to
modulate
hydraulic
pressure
to
that
brake
caliper
.



The
traction
control
system
works
in
conjunction
with
ABS
The
rear
wheels
are
modulated
asa
pair,
controlled
by
a
sin-



and
the
engine
management
system
to
enhance
vehicle
con
gle
solenoid
valve
.



trol
.
The
main
function
of
the
AST
system
is
to
maintain
the
rolling

contact
between
the
tires
and
the
road
surface
under
al¡
driving
E36
cars
equipped
with
ABS/AST
utilize
a
four
channel
sys-



conditions
.
This
is
achieved
through
exact
application
and
tem,
which
functionsexactly
as
the
three
channelsystem



management
of
braking
and
drivetrain
forces
.
above,except
that
the
rear
wheels
are
modulated
individually
.

IDLE
SPEED
CONTROL
VALVE

HROTTLE
PLATE

6
.

Í
III

i



ADS
ACTU
AT
OR

THROTTLE
PLATE
POSITION
SENSOR

DME

Fig
.
6
.
All
Season
Traction
(AS)
works
withother
drivetrain
systems
to
enhance
vehicle
control
.

INTEGRATED
SYSTEMS

The
throttle
control
system
used
in
AST
is
illustrated
in
Fig
.

MASS
AIR
FLOW
SENSOR

JADS
THROTTLE
PLATE
POSITION
SENSOR

0013006

300-6



SUSPENSION,
STEERING
AND
BRAKES-GENERAL

BATTE
RY

KL
30

ECM
MAIN
C~
RELAY



KL
15

DSC
SWITCH

LF1
;1~lZZ~



nSLn

l'
z
sJ



WHEEL

RF

c_
.

LR

r_
.
>
RR

ELECTRONIC
BRAKE
LIGHT
SWITCH

SPEED

SENSORS

Fig
.
7
.



Schematic
of
AII
Season
Traction
(AST)
system
.

INTEGRATED
SYSTEMS

EDC

POWER
SUPPLY



SOLENOID
RELAY
GROUND
CONTROL

POWER
SUPPLY
I'
1
ABS
PUMP

GROUND
CONTROLÍ
F



f
iJ
RELAY

INLET
(4X)
wxxuw
OUTLET
(4X)



-=-=--



AST
AST
INTAKE
IHYDRAULIC
-
=-

SWITCHING
=---

!
99001
!J

WHEEL
SPEED
X
4

DME
II

000001
-
f



1
UNIT

AGS

IKE
&
DMEI
PARK
BREVE

771
SWITCH

M
ALTERNATOR



AUXILIARY
THROTTLE

r
`



INDICATOR



POSITION
MOTOR
(ADS)

ABSPUMP



DIAGNOSIS

RELAY



lu~~~b

0013027

GENERAL

310
Front
Suspension

GENERAL
..
.
.
.
.
.
.
.
.
.
.......
.
........
.
310-1



FRONT
WHEEL
BEARINGS
..
.
.
.
.......
310-8

SHOCK
ABSORBERS
AND
SPRINGS
..
.
310-2



Front
wheel
bearing,
replacing
...
.
.
.
.
.
.
.
...
310-8

Strut
assembly,
removing
and
installing
.....
310-2



STABILIZER
BAR
..........
.
.
.
.
.
.
.
.
.
.
.
.
310-9

Strut
assembly,
disassembling



Stabilizerbar,
removing
and
installing
.
.
.
.
...
310-9

and
assembling
.
.
.
...
.
.....
.
.........
310-4

Ride
Height
.
.
.
.
.
.
.
.
.
.
.
.
.....
.
........
.
310-4



SUBFRAME
CROSSMEMBER
.
.
.
.
.
.
.
.
.
.
.
310-9

Subframe
crossmember,
CONTROL
ARMS
.
.
...
.
.
.
.
.
.
.
...
.
.....
310-5



removing
and
installing
.....
.
.
.
.
.
.
.
.
.
...
310-9

Control
arm,
removing
and
installing
....



..
310-5
Outer
control
arm
ball
joint,
replacing



Table

exce
t
M3
models



310-6



a
.
Front
Ride
Height
Specifications
..
.
.....
..
.
..
..
310-5
Control
arm
bushing,
replacing
.
.
.
...
.
.....
310-7

The
E36
front
suspension
is
shown
in
Fig
.
1
.
For
a
general



Specialservice
tools
arerequired
for
most
of
the
work
de-

description
of
the
front
suspension
and
components,
see
300



scribed
in
this
repair
group
.
Read
the
procedures
through
be-

Suspension,
Steering
and
Brakes-General
.



fore
beginning
any
job
.

Stabilizer
bar

Power
steering

fluid
cooler

Control



Strut
assembly
arm

Tierod

Fig
.
1
.



BMW
E36
front
suspension
.
(M3
suspension
shown
.
Others
are
similar
.)

FRONT
SUSPENSION



310-1

Steering
arm
0012132

GENERAL

310-2



FRONT
SUSPENSION

WARNING-

"
Physical
safety
could
be
impaired
if
procedures
described
here
areundertaken
without
the
proper
service
tools
and
equipment
.
Be
sure
to
have
the
right
tools
onhand
before
beginning
any
job
.

"
Do
notreuse
self-locking
nuts
or
bolts
.
They
are
designed
to
beused
only
once
and
may
fail
if
re-
used
.
Always
replace
self-locking
fasteners
any
timethey
are
loosenedor
removed
.

"
Do
not
install
bolts
and
nuts
coated
with
under-
coating
wax,
as
the
correct
tightening
torque
can-
not
beassured
.
Always
clean
the
threads
with
solventbefore
installation,
or
install
new
parts
.

"
Do
not
attempt
to
weld
or
straighten
any
suspen-
sion
components
.
Replace
damaged
parts
.

SHOCK
ABSORBERS
AND
SPRINGS

The
complete
front
strut
assembly
is
shown
in
Fig
.
2
.
Most

strut
assembly
components
are
available
asreplacement

parts
.

NOTE-

Struts
andlor
springs
shouldalways
be
replaced
in
parts
.

Strut
assembly,
removing
and
installing

1
.
Raisecar
and
remove
front
wheel
.

WARNING-

Make
sure
that
the
car
is
firmly
supported
on
jack
standsdesigned
for
the
purpose
.
Place
the
jack
standsbeneath
a
structural
chassis
point
Do
not
place
jack
stands
under
suspension
parts
.

2
.
Unbolt
brake
caliper
assembly,
keepingbrake
hose
connected
.
Detach
brake
hose
from
strut
assembly
.

Suspend
brake
caliper
from
chassis
using
stiff
wire
.
Re-
move
brake
rotor
.
See
340
Brakes
.

SHOCKABSORBERS
AND
SPRINGS

0011191
Fig
.
2
.



Front
strut
assembly
with
steering
arm,
front
hub,
front
spring
and
strut
upper
mount
.

3
.
Remove
ABS
wheelspeed
sensor
.
See
Fig
.
3
.

4
.
Disconnect
ABS
sensor
wire
harness
and
brake
pad
wear
sensor
wire
harness
(left
side
only)
from
strut
housing
.

5
.
OnM3
modeis
:
Disconnect
stabilizer
bar
link
from
strut
.

Fig
.
3
.



ABS
wheel
speed
sensor
mounting
bolt
(arrow)
.

NOTE-

Note
flats
on
stabilizer
bar
linkball
joint
for
placement
of
open
end
wrench
.

CAUTION-
Do
not
remove
center
strut
retaining
nut
.

8
.
Lower
strut
assembly
from
car
.

NOTE-

Store
the
removed
strut
assembly
upríght
.
Do
not
allow
it
to
líe
horizontally
or
upside-down
for
any
lengthoftime
.
If
íncorrect
storage
has
occurred,
place
the
strut
assembly
upríght
wíth
the
rod
fully
extended
for
at
least
24
hours
.

0012117

FRONT
SUSPENSION



310-3

6
.
Unbolt
splash
shield
and
steering
arm
from
strut
.
Sus-



Fig
.
4
.



Strut
and
steering
arm
assembly
.
pend
steering
arm
assembly
from
chassis
using
stiff
wire
.
See
Fig
.
4
.

1
.
Nut



6
.
Bolt
2
.
Strut



7
.
Bolt
3
.
ABS
wheel
speed
sensor



8
.
Flat
washer
4
.
Cable
holder



9
.
Self-locking
nut
5
.
Steering
arm



10
.
Washer
11
.
Bolt

9
.
Installation
is
reverse
of
removal
.
Be
sure
to
use
new

CAUTION-



self-locking
nuts
and
bolts
.

The
steering
arm
ball
joint
can
be
damaged
if
the



"
Use
new
steering
arm
mounting
bolts,
or
clean
bolts
arm
is
allowed
to
hang
unsupported
.



and
use
Locktite
®
270
orequivalent
thread-locking
compound
.

7
.
Support
strut
assembly
from
below
.
From
above,
re-



"
On
M3
models
:
When
attaching
stabilizer
link
to
strut,

move
three
strut
mounting
nuts
on
strut
tower
.



use
a
thin
wrench
to
hold
flats
on
link
parallelto
strut
.
"
Have
car
professionally
aligned
When
job
is
complete
.

Tightening
Torques

"
Brake
caliper
to
steering
arm
......
110
Nm
(81
ft-lb)

"
Road
wheel
to
hub
.........
100±10
Nm
(74
t7
ft-Ib)

"
Stabilizer
bar
link
to
strut
(M3)
.....
.
59
Nm
(44
ft-lb)

"
Steering
arm
to
strut
housing

"
(encapsulated
bolts-always
replace)
107
Nm
(78
ft-lb)

"
Strut
assembly
to
strut
tower

(self-locking
nuts)
........
...
..
..
.
24
Nm
(16
ft-Ib)

SHOCK
ABSORBERS
AND
SPRINGS

310-
4



FRONT
SUSPENSION

Strut
assembly,

disassembling
and
assembling
-
Be
sure
upper
spring
pad
is
correctly
installed
to
upper

NOTE-



spring
plate
and
spring
end
is
correctly
seated
in
up-
Springs
andlor
struts
should
always
be
replaced
in



per
and
lower
spring
plates
.

pairs
.



"
Use
a
new
self-locking
top
(center)
nut
.
Tighten
nut
fui-
¡y
before
releasing
spring
compressor
.

Replacing
the
upper
strut
mount,
spring
and
strut
requires



"
Have
car
professionally
aligned
when
job
is
complete
.

that
the
strut
first
bedisassembled
.
For
a
guide
to
the
parts

during
strut
replacement,
see
Fig
.
5
.
Tightening
Torques

WARNING-



"
Upper
strut
mount
to
strut
shaft
(seif-locking
nut)

Do
not,attempt
to
disassemble
thestruts
without
a



shaft
with
external
hexagon
......
..
65
Nm
(48
ft-1b)

springcompressordesignedspecificallyforthisjob
.



shaft
with
interna¡
hexagon
.......
..
44
Nm
(32
ft-Ib)

"
Road
wheel
to
hub
........
.100±10
Nm
(74
±7
ft-lb)

1
.
Remove
strut
assembly
as
described
earlier
.
Place
in

secure
support
.
Ride
Height

2
.
Using
spring
compressor,
compress
spring
until
spring

force
onupper
mount
is
relieved
.



Ride
height
is
measured
from
the
lower
edge
of
the
wheel

arch
to
the
bottom
edge
of
the
wheel
rim
.
See
Fig
.
6
.

WARNING
-

Make
sure
the
spring
compressor
grabs
the
spring



lf
the
ride
height
is
outside
the
specification
listed,
new

fully
and
securely
before
compressing
it
.



springs
should
be
installed
.
Be
sure
to
have
theold
spring

code
number
on
hand
when
ordering
new
spring
.

3
.
Pry
protective
cover
off
top
ofstrut
assembly,
then
re-

move
top
(center)
nut
andwasher
whileholding
strut



NOTE-

shaftstationary



The
spring
part
number
is
stamped
near
the
end
of
the
spring
cofls
.

4
.
Remove
upper
strut
mount
and
related
components
.

5
.
Release
spring
compressor
carefully
and
evenly,
allow-

ing
spring
lo
expand
slowly

1
Self-locking
hex
nut



Absorber/

Flat
washer



bump
stop

Nut

Cover

Upper



~
strut
mount



Pin
Z



Piston
bellows

Flat
washer



r
i

t1



~



1
Upper
spring
plate

1



1



1

Upper
spring
pad



I



1
-



,



Lower
spring
pad

-
Í



0012136

Fig
.
5
.



Front
spring,
spring
plate
and
related
parts
.

SHOCKABSORBERS
AND
SPRINGS

6
.
Assembly
is
reverse
of
disassembly,
noting
the
follow-

ing
:

Table
a
lists
front
suspension
ride
height
specifications
.

These
specifications
apply
to
a
car
in
a
normally
loaded
posi-

tion
.
When
checking
ride
height
or
installing
suspension
com-

ponents
that
require
thecar
to
be
"normally
loaded,"load
the

car
as
follows
: