front suspension BMW M3 1996 E36 User Guide

119-
6



LUBRICATION
SYSTEM

17
.
Raise
engine
as
much
as
possible
.
Check
carefully
for



22
.
Installation
is
reverse
of
removal
.

obstructions,
wiring
harness
clearance
and
pinched

hoses
or
lines
as
engine
is
raised
.



"
When
installing
oil
pan,
apply
a
b



d
of
non-hardening

sealing
compound
(3-Bond
1209
0
or
equivalent)
to

18
.
Remove
oil
pan
mounting
bolts
and
lower
oil
pan
to



front
and
rear
end
cover
seam
areas
on
block
.

subframe
crossmember
.



"
Position
oil
pump
pickup
tube
and
oil
pan
onto
block

and
install
pickup
tube
using
a
new
gasket
.

"
Be
sure
tab
on
gasket
faces
down
towards
intake
of

NOTE-



pickup
tube
.
If
the
oil
pan
does
not
separate
easily
from
the
engine



"
Tightenforward
oil
pan
screws
first,
then
tighten
rear
.

cylinder
block,
afew
taps
with
arubber
mallet
should



"
Fill
engine
with
oil
as
described
in
020
Maintenance
break
it
free
.
Do
not
pry
the
oil
pan
loose
.



Program
.

"
After
adding
engine
oil,
start
and
run
engine
.
Raise
en-

19
.
Remove
oil
pump
sprocket
mounting
nut
.
See
Fig
.
9
.



gine
speed
to
2,500
rpm
until
oil
pressure
warning

Lift
sprocket
off
together
with
drive
chain
.



lampgoes
out(about
5seconds)
.

Fig
.
9
.
Oil
pump
sprocket
mounting
nut
(left-hand
thread)
on
6-cylin-



OII
pan,
removing
and
installing

derengine(arrow)
.



(6-cylinder
engine,
1993
and
later
modeis)

NOTE-

The
oíl
pump
sprocket
nut
has
left
hand
threads
.

20
.
Unbolt
oil
pump
pickup
tubefrom
oil
pump
.
Unbolt
oil

pump
from
engine
block
.
See
Oil
pump,
removing

and
installing
(6-cylinder
engine)
.

21
.
Remove
oil
pan
from
rear
.

Tightening
Torques

"
Engine
mount
to

suspension
crossmember(M10
nut)
..
42
Nm
(31
ft-Ib)

"
Oil
pan
to
engine
block
(M6
bolt)

8
.8
grade
....
..
.
...
...
.
........
10
Nm
(89
in-lb)

10
.9
grade
.
.
..
.
..
...
.
.
.
.
.
.....
12
Nm
(106
in-lb)

"
Oil
pump
to
engine
block
.
...
...
.
..
22
Nm
(16
ft-Ib)

"
Oil
pump
sprocket
to
oil
pump
shaft

(M1
0x1
left-hand
thread)
...
..
.
.
..
.
25
Nm
(18
ft-Ib)

"
Power
steering
pump
to
bracket

(self-locking
nuts)
.....
.
....
..
.
...
22
Nm
(16
ft-lb)

"
Power
steering
pump
bracket
to
engine

block
or
oil
pan
(self-locking
nuts)
.
..
22
Nm
(16
ft-Ib)

NOTE-

Cars
built
after
9/92
use
a
different
suspension
cross-

member
¡han
earfier
productíon
cars
.
Oil
pan
removal

procedure
on
the
later
cars
requíres
that
the
engine
be

supported
from
aboye
and
the
front
suspension
cross-

member
be
unbolted
and
loweredfrom
the
chassis
.

1
.
Raisecar
and
place
securely
on
jackstands
.

2
.
Remove
splash
shield
fromunder
engine,
if
applicable
.

3
.
Drain
engine
oil
as
descríbed
in
020
Maintenance
Pro-

gram
.

4
.
Remove
alternator
cooling
duct
from
alternator
and
ra-

diator
support
.

5
.
Remove
air
filter
housingcomplete
with
mass
air
flow
sensor
.
See113
Cylinder
HeadRemoval
and
Instal-
lation
.

6
.
Remove
oil
dipstick
guide
tube
mounting
bolt
.
Discon-
nect
oil
separator
hose
frombase
of
guide
tube
and
re-
move
tubefrom
oil
pan
(where
applicable)
.
See
Fig
.
10
.

NOTE-

The
guide
tube
is
sealed
in
the
blockusing
an
O-ring
.
Check
that
the
O-ring
comes
out
with
the
tube
.
Use
a
new
O-ring
when
installing
the
tube
.

Fig
.
10
.
Oil
dipstick
guide
tube
being
removed
.
Use
new
O-ring
(ar-
row)
during
installation
.

7
.
M50/S50US
engine
:
Using
a
clean
syringe,
remove
power
steering
fluid
from
fluid
reservoir
.
Disconnect
power
steering
fluid
lines
from
steering
rack
.
See
320
Steering
and
Wheel
Alignment
.

8
.
M52/S52US
engine
:
Unbolt
power
steering
reservoir
from
engíne,
then
tie
to
chassis
with
wire
.

9
.
Insta¡¡
engine
lifting
equipment
atfront
engine
lifting
point
and
raise
engine
approximately
5
mm
('/a
inch)
until
engineweight
is
supported
.
See
Fig
.
11
.

10
.
Workingbeneath
car,
separate
steering
column
shaft
from
steeringrack
at
universal
joint
.

"
Mark
steering
column
shaft
jointto
steering
rack
spin-

dle
.
Point
wheels
straight
ahead
before
disconnecting
shaft
from
rack
.
See
320
Steering
and
Wheel
Align-
ment
.

LUBRICATION
SYSTEM



119

Fig
.
11
.
Engine
lifting
equipment
shown
installed
acrossengíne
.

CA
UTION-

In
order
to
avoid
the
need
for
front-end
realign-
ment,
donot
unbolt
power
steering
rack
from
sus-
pension
crossmember
.

11
.
Support
suspension
crossmember
from
below
using
appropriate
jacking
equipment
.

12
.
Loosen
nuts
at
top
of
left
and
right
side
engine
mounts
.
Remove
nuts
from
bottom
of
left
and
right
side
engine
mounts
.

13
.
At
left
and
right
sides,
unbolt
control
arm
bushíng
carri-
ers
from
body
.
Disconnect
stabilizer
bar
links
fromcon-
trol
arms
.
Refer
to
Fig
.
3
.

14
.
Remove
bolts
from
left
and
right
sides
of
suspension
crossmember
and
lower
front
axle
as
far
as
possible
.

15
.
Remove
fuelline
clamping
brackets
from
oil
pan
.
On
cars
with
automatic
transmission,
remove
ATF
cooler
line
brackets
from
oil
pan
.

16
.
Remove
oil
pan
screws
.
Lower
and
remove
oil
pan
for-
ward
to
remove
.

CA
UTION-

If
the
oil
pan
does
not
separate
easily
from
the
en-
gine
cylinder
block,
a
few
taps
with
a
rubber
mallet
shouldbreak
it
free
.
Do
notpry
the
oil
pan
loose
.

OIL
PAN

119-
8



LUBRICATION
SYSTEM

17
.
Installation
is
reverse
of
removal
.

"
Thoroughly
clean
all
old
gasket
material
from
mating

surtaces
anduse
a
new
gasket
.

"
Applya
small
amount
of
non-hardening
sealer
(3-Bond

1209
0
or
equivalent)
to
oil
pan
gasket
directly
below

joints
for
and
cover
and
front
timing
case
cover
.
See

Fig
.
12
.

"
Tighten
oil
pan
bolts
starting
at
front
first,
working
to-

wardback
(transmission)
end
.

"
Fill
engine
with
oil
as
described
in
020
Maintenance

Program
.

"
After
addingengine
oil,
start
and
run
engine
.
Raiseen-

gine
speed
to
2,500
rpm
until
oíl
pressure
warning

lampgoes
out
(about
5seconds)
.

OIL
PUMP

applied
(arrows)
.
Apply
a
bead
3
mm
wideby
2
mm
high
.

WARNING
-

"
Always
use
new
bolts
when
mounting
the
sub-

frame
to
the
body
.
The
one-time
only
bolts
should
be
replaced
any
timethey
are
removed
.

"
Special
installation
instructions
apply
when
in-
stalling
the
front
suspension
crossmember
to
the
body
.
See
310
Front
Suspension
for
fastener
specifications
and
tightening
torques
.

Fig
.
12
.
Joint-mating
areas
at
oil
pan
gasket
where
sealer
should
be

Center
the
steering
spindle
to
the
steering
rack
before
in-

stalling
the
steering
column
shaft
.
See
320
Steering
and

Wheel
Alignment
for
more
specific
procedures
.

Tightening
Torques

"
Control
arm
bushing
carrier

to
body
(M10
bolt)
...............
47
Nm
(35
ft-Ib)

"
Engine
mount
to

suspension
crossmember(M10
nut)
..
42
Nm
(31
ft-Ib)

"
Oil
pan
to
engine
block
(M6
bolt)

8
.8
grade
...........
.......
....
10
Nm
(89
in-lb)

10
.9
grade
...........
..
...
...
.
12
Nm
(106
in-lb)

"
Stabilizer
bar
link

to
control
arm
(M10
nut)
.......
....
42
Nm
(31
Ib-ft)

"
Steering
column
universal
joint

to
steering
rack
spindle
(M8
bolt)
....
19
Nm
(14
ft-Ib)

"
Suspensíon
crossmember

to
body
...
...
.
...
..
.
.
See
310
Front
Suspension

OIL
PUMP

Oil
pump,
removing
and
installing

(4-cylinder
engine)

Oil
pressure
on
M42
and
M44
engines
is
generatedbya

gear-type
pump
mounted
to
the
rear
of
the
front
engine
cover

(timing
chaincase)
.
The
pump
is
gear-driven
off
the
front
of

the
crankshaft
.

NOTE-

Oil
pump
removal
requires
lowering
of
the
front
sus-

pension
and
removal
of
the
oil
pan,
as
well
asremoval
of
the
timing
chain
assembly
.

1
.
Disconnect
negative
(-)
battery
cable
from
battery
.

CAUTION-

Prior
to
disconnectiog
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this
manual
on
paga
vÍii
.

2
.
Drain
engine
oil
as
described
in
020
Maintenance
Pro-

gram
.

3
.
Withengine
cold,
drain
coolant
.
See
170
Radiator
and

Cooling
System
.

4
.
Remove
top
cover
from
oil
filter
housing
to
allow
engine

oil
to
drain
into
oil
pan
.
Remove
oil
pan
as
described

earlier
.
Reinstall
oil
filter
cover
.

5
.
Remove
alternator
.
Unbolt
power
steering
pump
from

bracket,
then
remove
alternator
mountíng
bracket
.
See

121
Battery,
Starter,
Alternator
.

6
.
Remove
crankshaft
vibration
damper
andhub
.
Then
re-

move
upper
and
lower
timing
chain
covers,
complete

timingchain,
chain
sprockets
and
chain
guides
.
See

117
Camshaft
Tíming
Chain
.

119-
1
0



LUBRICATION
SYSTEM

Oil
pump,
removing
and
installing

(6-cylinder
engine)

Oil
pressure
on
the
6-cylinder
engines
is
generated
by
a
gear-type
pump
bolted
to
the
bottom
of
the
engine
block
.
The
oil
pump
is
chain
driven
off
the
front
of
the
crankshaft
.

NOTE-

Oil
pump
removal
requires
raising
the
engine
(cars
built
up
to
9-92)
or
lowering
the
front
suspension
crossmem-
ber
(cars
built
from
9-92)
to
remove
the
oil
pan
.

1.
Drain
oil
as
described
in
020
Maintenance
Program
.

2
.
Remove
oil
pan
as
described
earlier
.

3
.
Remove
oil
pump
sprocket
mounting
nut
(left-hand
thread)
.
See
Fig
.
16
.
Lift
sprocket
off
together
with
drive
chain
.

Fig
.
16
.
Oil
pump
sprocket
mounting
nut
(left-hand
thread)
on
6-cylin-
der
engine
(arrow)
.

4
.
Remove
mounting
bolts
from
oil
pump
and
oil
pump
pickup
tube
.
Withdraw
pump
.

NOTE-

Note
any
spacers
between
pump
and
engine
block
.
See
Fig
.
17
.

"
Note
position
of
locating
dowels
.

OIL
PUMP

811186

0011952

Fig
.
17
.
Oil
pump
mounting
points
(1)
and
pickup
tube
mountíng
points
(2)
.

5
.
Remove
coverfrom
oil
pump
and
check
for
wear
or
scoring
.
Spin
oil
pump
shaft
and
check
that
gears
turn
smoothly
.
Replace
pump
if
gears
spinwith
difficulty
or
any
wear
is
present
.

6
.
Installation
is
reverse
of
removal,
noting
the
following
:

"
Align
sprocket
splines
to
oil
pump
shaft
splines
before

tightening
sprocket
nut
.

Tightening
Torques

"
Oil
pump
to
engine
block
(M8)
......
22
Nm
(16
ft-Ib)

"
Oil
pan
to
engine
block
(M6
bolt)

8
.8
grade
..
...
.
...
...
.
.........
10
Nm
(89
in-lb)

10
.9
grade
.
...
.
..
....
.
........
12
Nm
(106
in-lb)

"
Oil
pump
sprocket
to
oil
pump
shaft
(M1
0x1
left-hand
thread)
..........
25
Nm
(18
ft-Ib)

230-
6



MANUAL
TRANSMISSION

Transmission,
removing
and
installing

1
.
Disconnect
negative
(-)
cable
from
battery
.

CAUTION-

Prior
to
disconnecting
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this
manual
onpage
viii
.

2
.
Insta¡¡
enginesupportacrossengine
bay
.
Raise
engine

so
that
weight
of
engine
ís
supported
.
See
Fig
.
10
.

Fig
.
10
.
Engine
support
equipment
used
to
support
engine
from
above
before
removing
transmission
.

3
.
Raise
vehicle
to
gain
access
to
underside
of
car
.

4
.
Support
transmission
with
transmission
jack
.
lf
applica-
ble,
remove
reinforcing
cross
brace
from
belowen-
gine/transmission
.

5
.
Disconnect
harnesscon
nector
from
reverse
light
switch
on
transmission
.

6
.
Remove
completeexhaustsystem
and
heat
shield
.
See
180
Exhaust
System
.

NOTE-

Disconnect
oxygensensor
hamess
connector(s)be-
fore
lowering
exhaust
system
.

7
.
Remove
driveshaft
.
See260
Driveshaft
.

8
.
Disconnect
shift
rod
from
transmission
selectorshaft
.
See
Fig
.
11
.

9
.
Disconnect
shift
console
fromtop
of
transmission
.
See
250
Gearshift
Linkage
.

TRANSMISSION
REMOVAL
AND
INSTALLATION

Washers

Shift



Shift
rod

rod



retaining
clip

0
0
,

Fig
.
11
.
Shift
lever
to
transmission
connection
.

Shift
console

0012024

10
.
Unbolt
clutch
slave
cylinder
from
sideof
transmission
.

Do
not
disconnect
fluid
hose
.
Suspend
slavecylinder

from
chassis
using
stiff
wire
.

CAUTION-

Do
not
operate
clutch
pedal
with
slave
cylinder
re-
moved
from
transmission
.

11
.
Support
transmission
from
below
with
jack
.
Remove
rear

support
crossmember
from
transmission
.
See
Fig
.
12
.

Fig
.
12
.
Rear
transmission
crossmember
(arrow)
.

12
.
Lower
transmission/engine
assembly
until
it
rests
on
front
suspension
crossmember
.

CAUTION-

Tilting
the
engine
to
lower
thetransmission
can
lead
to
damage
to
various
componente
due
to
lackof
clearance
at
rear
of
engine
-On
cars
with
AST
remove
throttle
body
before
tilt-
ing
engine
.
-Remove
brace
fluid
reservoir
if
necessary
.

0013135

DRIVESHAFT
SERVICE
.
...
.
.
.
...
.
..
.
.
.260-3

Driveshaft,
aligning
...............
.
...
.
.
260-3

Driveshaft,
removing
..............
.
.
.
.
.
.
260-4

260
Driveshaft

DRIVESHAFT
260-1

GENERAL
.
.
.
.
.
.
.
.....
.
.
.
........
.
...
.
260-1



Driveshaft,
installing
.
....
.
..
.
............
260-4

Flex-disc,
replacing
.....
.
.
.
.............
260-5
TROUBLESHOOTING
..
.
.
.
...
.
.........
260-1



Center
bearing
assembly,
replacing
.
......
.260-6
Frontcentering
guide,
replacing
..
.
.......
.
260-7

TABLE

a
.
Driveshaft
Troubleshooting
.
.
...
......
.
....
..
.
.
260-2

GENERAL



NOTE-

For
rear
drive
axlerepair
information,
see330
Rear
The
two-piece
driveshaft
is
joined
in
thecenter
by
a
sliding



Suspension
.
splined
coupling
.
This
coupling
compensates
for
fore
and
aft
movement
of
the
drive
line
.
The
driveshaft
ís
connected
to
the



Driveshaft
noise
or
vibration
may
be
caused
by
worn
or
transmission
bya
rubber
flex-disc
and
to
the
final
drive
by
a



damaged
components
.
Check
the
universal
joints
for
play
.
universal
joint
.
It
is
supported
in
the
micidle
by
a
center
support



With
the
driveshaft
installed,
pull
and
twist
the
driveshaft
while
bearing
.
The
bearing
is
mounted
in
rubber
to
isolate
vibration
.



watching
the
joint
.
The
BMW
specificationfor
play
is
very
See
Fig
.
1
.



small,
so
almost
any
noticeableplay
could
indicate
a
problem
.

TROU
BLESHOOTING



Check
thetorque
of
thefasteners
at
the
flange
connections
.
Check
therubber
of
the
flex-disc
and
center
bearing
for
dete

The
source
of
driveline
vibrations
and
noise
can
be
difficult



rioration
or
tearíng
and
check
for
preload
at
the
center
bearing

to
pinpoint
.
Engine,
transmission,
rear
axle,
or
wheel
vibra-



with
a
visual
inspection
.
Check
the
driveshaft
for
broken
or

tions
can
be
transmitted
through
the
driveshaft
to
the
car



missing
balance
weights
.
The
weights
are
welded
tabs
on
the

body
.
Noises
from
the
rear
of
thecar
may
be
caused
by
final



driveshaft
tubes
.
In
addition
to
inspecting
for
faulty
driveshaft

drive
problems,
orby
faulty
wheel
bearings,
drive
axies,
or



parts,
the
installed
angles
of
the
driveshaft
should
also
be

evenworn
or
improperly
inflatedtires
.



considered
.

Flex-disc

Center
universal
joint

Fig
.1
.



Driveshaft
and
final
drive
assembly
.

Rear
section
Splined
shaft



of
driveshaft
Center
support



`



Clamping
sleeve
bearíng
assembly

Differential
inputflange

0013110

TROUBLESHOOTING

SUSPENSION,
STEERING
ANDBRAKES-GENERAL



300-1

300
Suspension,
Steering

and
Brakes-General

GENERAL
.....
.
....
.
.....
.
.
.
........
.300-1



M3
SUSPENSION
AND
BRAKES
.......
.
...
300-7

Front
Suspension
..........
.
.
.
...
.
.....
300-1

Steering
...
.
.
.
.
.
....
.
.
.
...
.
.
.
...
.
...
.
.
300-2



SUSPENSION
AND
STEERING

Rear
Suspension
....
.
.
.
...
.
.
.
...
.
.....
300-2



TROUBLESHOOTING
..
.
.
.
.............
300-7

Brakes
.
.
.
.
.
.
.
.
....
.
...........
.
.
.
.
.
.
300-2

Tires
and
wheeis
.
................
.
.
.
.
.
.
300-2



TABLE

a
.
AST
Indicator
Lamp
Function
..
..
.
..
.
.........
300-5

INTEGRATED
SYSTEMS
.........
.
.
.
.
.
.
300-2



b
.
Suspension
and
Steering
Troubleshooting
......
.300-8

Antilock
Brake
System
(ABS)
.......
.
.
.
.
.
.
300-2

Al¡
Season
Traction
(AST)
.........
.
.
.
.
.
.
300-4

GENERAL



Front
Suspension

This
section
covers
general
information
for
front
and
rear



The
lower
control
arms
connect
the
front
suspension
struts

suspension,
the
steering
system,
and
the
brakíng
and
traction



to
mounting
points
on
the
subframe
crossmember
and
the

control
systems
.



body
.
See
Fig
.
2
.

The
BMW
E36
suspension
and
steering
systems
are
engi-

neered
to
provide
a
compromise
between
taut,
responsive
handling
and
ride
comfort
.
Although
the
front
and
rear
suspen-
sion
assemblies
are
independent
subsystems,
they
work
to-

gether
to
achieve
BMW's
overall
combination
of
precise

handling
and
comfort
.
See
Fig
.
1
.

Fig
.
1
.



BMW
E36
front
and
rear
suspension
systems
.

Each
front
strut
assembly
includes
a
shock
absorber
car-

tridgeinside
the
tubular
strut
housing
and
a
large
coil
spring
.

The
upper
strut
mount
bearing
allows
the
strutto
turnwith
the

wheels
.
The
lower
end
of
the
strut,
which
includes
the
stub
axle
for
the
front
wheel,
connects
to
a
ball-joint
on
the
control
arm
.

0013098

GENERAL

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-

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

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