1993 BMW M3 ind

NOTE-

The
traction
control
system
referred
to
as
AST
(all
sea-
son
traction)
may
also
be
referred
to
as
ASC
(Automat-
ic
Stability
Control)
and
ASC+T
(Automatic
Stability
Control+Traction)
.

The
AST
system
improves
traction
by
electronically
apply-

ing
the
rear
brakes
when
therear
drive
wheels
are
spinning
at

a
faster
rate
than
the
front
wheels
.
The
combined
ABS/AST

control
module,
operating
through
the
ABS
hydraulic
control

unit,
modulates
braking
force
at
therear
wheels
.

In
addition,
AST
uses
retarded
ignition
timing
and
an
auxil-iary
engine
throttle
plate
to
reduceengine
torque
and
maintain

vehicle
stability
.

The
auxiliary
throttle
plate
is
held
open
by
spring
pressure
.

The
AST
system
actívates
the
auxiliary
throttie
position
motor

(ADS)
to
cose
the
AST
throttle
as
needed
.
This
reduces
the

volume
of
engine
intake
air
.
Due
to
the
throttle
closing
very
rapidly
during
AST
operationthe
driver
cannot
increase
theengine
power
output
regardless
of
how
far
theaccelerator
pedal
is
pushed
to
the
floor
.

The
auxiliary
throttle
plate
is
placed
ahead
of
the
conven-

tional
throttle
plate
in
the
throttle
body
.

Traction
control
also
comes
into
operationduringdecelera-
tion
.
Decelerating
on
snowy
or
icy
road
surfaces
can
lead
to
rear
wheel
slip
.
If
a
rear
wheel
startsto
drag
or
lock
up
when

the
throttle
is
closed
rapidly
orduringdownshifting,the
AST
system
can
limit
the
problem
by
advancing
the
ignition
timing
.

A
switch
on
the
center
console
is
used
to
togglethe
AST
on

or
off
.

The
AST
system
is
designed
to
be
maintenance
free
.
There

are
no
adjustments
that
can
be
made
.
Repair
and
trouble-
shooting
of
the
AST
system
requires
special
test
equipment

andknowledgeand
should
be
performed
only
by
an
autho-

rized
BMW
dealer
.
Table
a
lists
theconditions
indicated
by

the
AST
indicator
light
in
the
instrument
cluster

SUSPENSION,
STEERING
AND
BRAKES-GENERAL



300-5

Tablea
.
AST
Indicator
Lamp
Function

Indicator
lamp



1
Condition



1
Comment

Light
on



Normal
AST
start-



Automatic
AST
up



self-test

Light
off



AST
monitoring



Automatic
AST
op-
mode



eration

Press
AST
button,



AST
off
(disabled)



Rocking
the
car
tolight
comes
on



getout
of
snow
or
other
loose
surface
Driving
with
snow
chains

Press
AST
button
:



AST
monitoring



Automatic
AST
op-
light
goes
out



I
mode



eration

Light
flashes



AST
active
mode



I
Normal
AST
oper-
ation
as
it
controls
wheel
speed

Light
stays
on
af-



Defect
in
AST



Consult
BMW
ter
start
up
or



dealer
for
diagno-
comes
on
while



sis/repair
driving



(Vehicle
operation
remains
normal)

WARNING
-

Even
a
car
with
AST
is
subject
to
the
normal
physi-
cal
laws
.
Avoid
excessive
speeds
for
the
road
con-
ditions
encountered
.

CAUTION-
"
If
the
tires
on
the
carare
of
different
makes,
the
AST
system
may
over-react
.
Only
fit
tires
of
the
same
make
and
tread
pattem,

"In
adverse
conditions,
such
as
trying
to
rock
the
car
outof
deep
snow
or
another
soft
surface,
or
when
snow
chainsare
fitted,
it
is
advisable
to
switch
off
AST
and
allow
the
cars
driveline
to
op-
erate
conventionally
.

INTEGRATED
SYSTEMS

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

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

6
.
Installation
is
reverse
of
removal
.

"
Make
sure
control
arm
ball
joint
taper
bore
is
clean
and
free
of
any
corrosion
.
"
Press
new
balljoint
into
position,
making
sure
to
align
balljoint
guide
with
mark
made
earlier
.
"
Verify
that
locking
clip
on
new
ball
joint
faces
towards
center
of
vehicle
.

Tightening
Torques

"
Control
arm
ball
jointto
steering
arm
.
65
Nm
(48
ft-Ib)
"
Stabilizer
bar
link
to
control
arm
(M8)
42
Nm
(31
ft-Ib)
"
Road
wheel
to
hub
.
...
...
.
.
100±10
Nm
(74t7
ft-lb)

Control
arm
bushing,
replacing

Control
arm
bushings
should
aiways
be
replaced
in
pairs
and
the
two
bushings
and
bushing
carriers
should
have
the
same
markings,
indicating
same
manufacturer
.

1
.
Raisecar
.

WARNING-
Make
sure
that
the
car
is
firmly
supportedonjackstandsdesigned
for
the
purpose
.
Place
the
jackstands
beneath
a
structural
chassis
point
.
Do
not
place
jack
stands
undersuspension
parts
.

2
.
Unbolt
control
arm
bushing
carrier
from
body
.

3
.
Mark
installed
position
of
bushing
to
control
arm
.
See
Fig
.
11
.

assembly
off
control
arm
.

lnl~

0012145

FRONT
SUSPENSION



310-
7

NOTE-

The
kerosene-like
special
lubricant
is
used
only
asan
aid
in
installing
the
bushing
to
the
control
arm
stub
.
Workmustbe
carried
out
in
as
short
a
time
as
possible
.
Within
30
minutes
the
control
arm
bushing
will
be
`glued"
in
position
on
the
control
arm
.

CAUTION-

BMW
part
numbers
areprovided
for
reference
only
and
are
subject
to
change
.
Always
rely
on
an
authorized
BMW
dealerparts
department
for
the
most
up-to-date
information
.

6
.
Press
new
rubber
control
arm
bushing
assembly
onto
the
end
of
control
arm
to
proper
depth
(as
marked)
.

NOTE-

Be
sure
toreinstall
the
bushing
carrier
to
the
control
arm
correctly
.
The
carrier
has
centering
bores
on
side
.
This
side
must
face
up
towards
body
.
See
Fig
.
12
.

Fig
.
12
.
Control
arm
bushing
carrier
centering
bores
must
face
up
.

7
.
Immediately
bolt
control
arm
bushing
carrier
to
body,
torque
boits
and
lower
car
to
ground
.

Tightening
Torques

"
Control
arm
bushing
carrier
to
body
.
.
47
Nm
(34
ft-ib)
Fig
.
11
.
Before
removingbushing
from
control
arm,
mark
installed
po-
sition
of
old
bushing
to
control
arm
.
Insta¡¡
new
bushing
in
same
position
.



8
.
With
car
lowered
to
ground
and
loaded
as
described
earlier,
bounce
suspensiona
few
times,
then
leave
car

4
.
Using
appropriate
press
tools,
pull
control
arm
bushing



undisturbed
for
a
minimum
of
30
minutes
.

CAUTION-

5
.
Coat
end
of
control
arm
with
BMW
special
lubricant



I
Failure
to
follow
the
above
procedure
may
impair

part
no
.
8122
9
407284
.



the
car's
handling
and
stability
.

CONTROLARMS

310-
8



FRONT
SUSPENSION

FRONT
WHEEL
BEARINGS

The
front
wheel
bearings
are
permanently
sealed
and
re-

quire
no
maintenance
.
The
bearing
is
integral
with
the
wheel

hub
and
pressed
onto
the
steering
arm
stub
axle
.

Special
press
tools
are
requiredto
replace
the
front
wheel

bearings
.
Read
the
procedure
through
before
beginning
the

job
.

Front
wheel
bearing,
replacing

1
.
Raise
car
and
remove
wheel
.

WARNING-

Make
sure
that
the
car
is
firmly
supportedon
jack

stands
designed
for
the
purpose
.
Place
the
jack

stands
beneatha
structural
chassis
point
.
Do
not

place
jack
stands
under
suspension
parts
.

2
.
Pry
off
dust
cap
from
centerof
wheel
hub
.
Bend
back

staked
part
of
wheel
hub
(axle)
collar
nut
.
See
Fig
.
13
.

Fig
.
13
.
Staked
part
of
wheel
hub
collar
nut
to
be
bent
back
(arrow)
.

3
.
Remount
wheel
and
lug
bolts
.

4
.
Lower
canto
ground
.
With
an
assistant
applying
brakes,

loosen
collar
nut
.
Do
not
remove
completely
.

NOTE-

The
wheel
hub
collar
nut
is
tightened
to
a
torque
of
290
Nm
(214
ft-Ib)
.
Make
sure
the
car
is
firmly
on
the
ground
.

FRONT
WHEEL
BEARINGS

6
.
Remove
ABS
wheel
speed
sensor
.
Refer
to
Fig
.
3
.

7
.
Remove
brake
caliper
assembly
and
brake
rotor
as
de-

scribed
in
340
Brakes
.
Leave
brakehose
connected
to

caliper
.
Suspend
caliper
assembly
from
chassis
using

stiff
wire
.

8
.
Remove
wheel
hub
collar
nut
.

9
.
Remove
wheel
hub
with
integral
wheel
bearing
from

steering
arm
using
a
puller
.
See
Fig
.
14
.

0011200

Fig
.
14
.
Wheel
hub
with
integral
wheel
bearing
being
removed
using
a

puller
.

NOTE-
If
bearing
inner
race
stays
on
steering
arm,
remove
splash
guard
and
usetwo
jaw
puller
to
remove
race
.

10
.
Insta¡¡
splash
guard
and
new
dust
shield
behind
bear-

ing
.
Press
new
wheel
hub/bearing
assembly
on
using

appropriate
press
tools
.

NOTE-

When
pressing
the
wheel
hublbearing
on,
apply
force
only
to
the
bearing
inner
race
.

11
.
Install
new
collar
nut
.
Do
not
tighten
nut
to
its
final

torque
atthis
time
.

"
Install
brake
rotor
and
brake
caliper
.
See
340
Brakes
.

"
Mount
wheel
and
lug
boits
.
Lower
canto
ground
to
gain

leverage
.

12
.
With
an
assistant
applying
brakes,
tighten
collar
nut

and
then
stake
nut
toaxle
.

5
.
Raise
car
and
remove
wheel
.



13
.
Raisecar
and
remove
wheel
.

320-2



STEERING
AND
WHEEL
ALIGNMENT

3
.
Carefully
remove
airbag
from
front
of
steering
wheel
.

See
721
Airbag
System
(SRS)
.
Store
airbag
unit
in
a

safe
place
.

WARNING-

Improper
handling
of
theaírbag
could
cause
seri-
ous
ínjury
.
Store
theaírbag
with
the
horn
pad
facing
up
.
If
stored
facing
down,
accidental
deployment
could
propel
it
vlolently
into
the
air,
causíng
ínjury
.

4
.
Remove
steering
wheel
center
bolt
.
Lightly
punch
mark

or
scribe
position
of
steering
wheel
to
steering
column

shaft
.
See
Fig
.
1
.

0012687
Fig
.
1
.
Steering
wheel
center
bolt
(arrow)
.



Power
steering
pump,

removing
and
installing

POWER
STEERING
SYSTEM

5
.
Unlock
steering
wheel
by
turning
ignition
key
on
.
Re-
move
steering
wheel
.

WARNING-

The
SRS
contact
reel
ís
mounted
to
the
rear
of
the
steering
wheel
hub
.
The
contact
reel
ís
a
wound
coil
ofwirethat
ensures
continuous
electrícal
contact
for
the
air
bag
unit
Once
the
steering
wheel
mounting
nut
or
bolt
is
removed
the
contact
reel
is
locked
in
the
center
position
and
its
position
must
not
be
al-
tered
.

6
.
Insta¡¡
steering
wheel
while
aligning
matching
marks
.
Make
sure
airbag
contact
ring
locking
pin
engages
cutout
in
contact
reel
.
Insta¡¡
steering
column
center
nut
.
Do
not
over-torque
.
See
Fig
.
2
.

7
.
The
remainder
ofinstallation
is
reverse
of
removal
.
Carefully
install
airbag
from
front
of
steering
wheel
.
See
721
Airbag
System
(SRS)
.

Tightening
Torque

"
Steering
wheel
to
steering
column
spindle
...
..
..
.
..........
63
Nm
(46
ft-Ib)

Fig
.
2
.



Insta¡¡
steering
wheel
so
that
locking
pin
in
column
aligns
with
cutout
in
contact
reel
(arrow)
.
Contact
reel
on
late
model
steering
wheel
may
vary
from
that
shown
.

POWER
STEERING
SYSTEM

Power
assist
is
províded
by
a
belt-driven
pump
on
the
lower

left
front
of
the
engine,
just
below
the
alternator
.
The
power

steering
fluid
resenroir
is
located
on
the
lower
left
front
of
the
engine
.

1
.
Empty
power
steering
fluid
reservoir
usingclean
sy-

ringe
.
Do
not
reuse
fluid
.

2
.
Raise
front
of
car
.

WARNING

Make
sure
thecar
is
firmly
supportedon
jack
stands
designed
for
the
purpose
.
Place
the
jack
stands
be-
neatha
structural
chassis
point
.
Do
not
place
jack
stands
undersuspension
parts
.

3
.
Remove
fluid
hoses
frbm
pump
.
Plug
openings
in
pump
and
in
hose
ends
.

4
.
Remove
drive
belt
from
power
steering
pump
.
See
020
Maintenance
Program
.

5
.
Remove
pump
mounting
bolts
and
remove
pump
.
See
Fig
.
3
.

330-2



REAR
SUSPENSION

Table
a
.
Rear
RideHeight
Specifications

Wheel
size



318,323,
325,



M3
modeis
328
modeis

17inch
std
.
suspension



546
mm
(21.69
in)
sport
suspension



~
535
mm
(21.06
in)



1
540
mm
(21
.26
in)

Maximum
variation
between
sides
:
10
mm
(0
.4in)
Maximum
deviation
from
specifications
:
10
mm
(0
.4in)

SHOCK
ABSORBERS
AND
SPRINGS

The
BMW
E36
independent
rear
suspension
is
shown
in

Fig
.
2
.
Refer
tothis
illustration
while
performing
repairs
on

components
covered
in
this
repair
group
.

NOTE-

Shock
absorbers
andlor
springs
shouldalways
be
re-
placed
in
pairs

i

Stabilizer
bar
link

Trailing

arm
-

bushing

Fig
.
2
.



BMW
E36
rear
suspension
.

SHOCK
ABSORBERS
AND
SPRINGS

Lower
control
arm

Trailing
arm

front
bracket

WARNING
-

"
Do
not
reuse
self-locking
nuts
.
They
arede-

signed
to
beused
only
once
and
may
fail
if
re-

used
.
Always
replace
them
with
new
self-locking

nuts
.

"
Personal
injury
may
result
if
procedures
de-
scribed
here
are
undertaken
without
the
proper
service
tools
and
equipment
.
Be
sure
to
have
the
right
tools
onhand
before
beginning
the
job
.

"
Do
not
install
bolts
and
nuts
coated
with
under-
coating
wax,
as
correct
tightening
torque
cannot

be
assured
.
Always
clean
the
threads
with
sol-

vent
before
installation,
or
ínstall
new
parts
.
"
Do
not
attempt
to
weld
or
straighten
any
suspen-
sion
components
.
Replace
damaged
parts
.

Rear
shock
absorber,

removing
and
installing

1.
Raisecar
and
remove
rear
wheels
.

WARNING
-

Make
sure
that
thecar
is
firmly
supportedon
jack
stands
designed
for
the
purpose
.
Place
the
jack
stands
beneatha
structural
chassis
point
.
Do
not
place
jack
stands
undersuspension
parts
.

2
.
Remove
rear
speakers
.
See
650
Radio
.

3
.
Pryoutluggage
compartment
liner
retaining
clips
and
peel
back
liner
to
gain
access
to
upper
shock
absorber
mounting
nuts
.
See
Fig
.
3
.

Fig
.
3
.



Rear
shock
upper
mounting
nuts
(arrows)
in
luggage
com-
partment
.
Liner
hasbeen
peeled
back
.

NOTE-

On
convertible
models,
the
uppershock
absorber
mount
is
in
the
convertible
top
compartment
behind
the
rear
seat
.

4
.
Support
trailing
arm
from
below
using
a
transmission

jack
orequivalent
.
See
Fig
.
4
.
Remove
shock
absorber

uppermounting
nuts
.

CAUTION-

The
shock
absorber
prevenís
the
drive
axle
and
trailing
arm
from
drooping
too
far,
so
always
sup-port
the
trailing
arm
before
removing
the
shock
.
Damage
to
drive
axle
CV
joints
can
result
.

0013224

5
.
While
supporting
shock
absorber,
carefully
remove

lower
mounting
bolt
.
Lower
shock
absorber
out
of

wheel
well
.

Fig
.
4
.



Support
rear
trailing
arm
from
below
before
removing
upper
or
lower
(arrow)
shock
mounting
.

6
.
Transfer
shocktopmounting
plate,
dust
coverand
relat-

ed
components
to
new
shock
absorber
.
See
Fig
.
5
.

'
Protective
cap

Upper
mounting
nut
14
Nm
(10
ft-Ib)

1120



Shock
upper
mount
,~,--~to
body
nuts
(renew)



I
-



'



~



24
Nm
(17
ft-Ib)



I
1
-Gasket
(renew)



I
1
pper
mount



I



Rear
I
shock
I
absorber
I
I
---spacer

REAR
SUSPENSION



330-
3

Rubber
bumper

Dust
shield

Fig
.
5
.



Rear
shock
absorber
assembly
.

Lower
mounting
bolt
77
Nm
I



(57
ft-Ib)

i

I

I
1
I

0013220
0013236

SHOCKABSORBERS
AND
SPRINGS