1997 BMW 540i front brake

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31 0-2
I Front Suspension
This repair group covers the repair and replacement of com-
ponents that make up the front suspension of E39 cars.
Two different types of steering systems are used in the E39
series. 6-cylinder
(5251,5281 and 530i) models are equipped
with a rack and pinion type steering system mounted to an
aluminum subframe.
V-8 (540i) models use a steering gear-
box type system mounted to a steel subframe.
See
300 Suspension, Steering and Brakes-General for a
description of the front suspension and components, as well
as specifications for setting ride height.
CAUTION-
Some E39 models are equipped with aluminum suspen-
sion components. The foiiowing cautions apply:
Due to the chemical and corrosion characteristics of
aluminum, do not bring into contact with battery acid.
* Do not clean with wire brushes with brass or iron bris-
ties. Only use brushes with stainless steei bristles.
Do not expose to flying sparks from grinding/cutting op-
erations.
* Do not subject to steei welding splashes.
Do not expose to temperatures over 80°C (176°F).
even for short periods. Temperatures in painting faciii-
ties are not a problem.
Special tools
Special service tools are required for most of the work de-
scribed in this repair group. In addition to the tools depicted in
the illustrations, avariety of press tools are necessaryfor con-
trol arm bushing replacement. Read the procedures through
before beginning any job.
31 2 210 I < Strut nut socket
(Tool No. 31 2 210)

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31 0-5
Front ~uspensionl
Front strut assembly, removing and
installing
- Raise car and remove front wheel.
WARNING-
Make sure that the car is firmly supported on jack stands de-
signed for the purpose. Place jack stands underneath struc-
tural chassis points.
Do not place jack stands under
suspension
parts.
- Unbolt bralte caliper assembly, lkeeping bralte hose connect-
ed. Secure brake caliper to body with wire. Do not let it hang
from brake hose. See
340 Brakes.
Remove ABS pulse sensor mounting bolts (arrows) and re-
move sensor from housing.
Detach ABS sensor wire harness and bralte pad wear sensor
wire harness (if equipped) from strut housing.
Loosen and remove stabilizer bar link mounting nut while
counterholding
link ball joint. Disconnect stabilizer link from
strut.
NOTE-
Use a thin wrench to counterhold shaft of stabilizer bar link
ball joint.
- Cars equipped with vertical headlight adjustment system:
Disconnect control arm from level sensor.
4 Remove outer tie rod end nut. Use BMW special tool 31 2
240 or equivalent to press tie rod end out of steering arm.

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31 0-8
Front Suspension
Slide strut assembly out of steering lknucltle pinch collar. If
necessary use pry bar.
CA UTIOI\C
Do notpullstrut out of steering knuckle with twisting motion.
This can scratch and damage the strut.
Disassemble and reassemble strut assembly as described
later.
When installing new strut, be sure to align locator letter (A)
on strut body with slot in steering
lknuckle pinch collar (6).
Struts are marked with L for left and R for right.
Remainder of installation is reverse of removal.
Make sure strut shoulder (below locator letter) bottoms out
in steering knuckle pinch collar.
Use new self-locking nuts and bolts.
When attaching stabilizer
lrnk to strut, use a thin wrench to
counterhold
link ball joint while t~ghtening nut.
- Have car professionally al~gned when job IS complete.
Tightening torques
Brake caliper to steering knuckle
110 Nm (81 ft-ib)
Road wheel to hub 120 ti0 Nm (89 t7 ft-lb)
Stabilizer bar
link to strut 65 Nm (48 It-lb)
Steering knucltle pinch bolt at strut 81 Nm (60 It-lb) - mountlng collar
Steering tle rod to steerlng knuckle 65 Nm (48 it-lb)
Strut assembly top to strut tower 24 Nm (18 it-lb)
- - -

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/~ront Susaension
Front suspension arms FRONT SUSPENSION ARMS
Scyllnder models (5251,5281,530i)
Control arms and tension struts are attached to the front sub-
Front suspension arms V-8 models (5401)
frame through rubber bushings and to the steering ltnuckles
by ball joints.
NOTE-
Tension struts are sometimes called thrust arms or thrust
rods.
Control arms or tension struts are sometimes called lower
front arms or lower rear arms.
Inspect ball joints for wear and looseness. lnspect bushings
for wear or fluid
lealts. The ball joint can only be replaced as
part of an entire suspension arm assembly. Some suspen-
sion arm
bushinas are available as re~lacement Darts. Al-
ways replace in pairs
NOTE-
Steering wheel vibration during braking (usually at road
speeds of
50 to 60 m.p.h.) are often causedby faulty suspen-
sion arm bushings, not out-of-true brake rotors.
Some special tools may be required to remove suspension
arms and to replace bushings. Read procedures through be-
fore beginning the job.
Control arm, removing and installing
(6-cylinder models)
- Raise car and remove wheel
Male sure
that the car is firmly supported on jack stands de-
signed for the purpose. Place jack stands underneath struc-
tural chassis points. Do not place jack stands under
suspension
parfs.
Cars equipped with vertical headlight adjustment system:
Disconnect control arm from level sensor.
Remove control arm fasteners (arrows). Lightly tap inner
control arm mounting bolt out of subframe.

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Front Suspension
< Use BMW special tool 31 2 240 or equivalent to separate
control arm ball joint from steering ltnuckle.
- When installing control arm, make sure all thread bores.
bolts, nuts and mating surfaces are clean.
- Install bushing end of control arm to subframe, using wash-
ers on both sides of bolt and a new self-locking nut. Do not
tighten nut at this time.
- Install control arm ball joint to steering lknucltle using a new
self-locking nut. Tighten fully.
- Install wheel and lower car.
- Load car to normal loaded position as described under Ride
height. See
300 Suspension, Steering and Brakes-Gen-
eral. Bounce suspension a few times.
- With car on ground and loaded, tighten control arm bushing
through-bolt.
Tightening torques
Control arm to steering ltnuckle
80 Nm (59 ft-lb)
Control arm to subframe 110 Nm (81 It-lb)
Road wheel to hub 120ilO Nm (8957 it-lb)
Control arm, removing and installing
(V-8 models)
- Raise car and remove wheel
WARNING-
Make sure that the car is firmly supported on jack stands de-
signed for the purpose. Place jack stands underneath struc-
tural
cliassis points. Do not place jack stands under
suspension parts.
Loosen and remove stabilizer bar link mounting nut
(A) while
counterholding ball joint
(B). Disconnect stabilizer link from
stabilizer bar.
- Cars equipped with vertical headlight adjustment system:
Disconnect control arm from level sensor.

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310-1 5
Front ~us~ension/
4 Remove control arm fasteners (arrows). Lightly tap inner
control arm mounting bolt out of subframe.
Use
BMW special tool 31 2 240 or equivalent to separate ball
joint from steering knuckle.
When installing control arm, make sure all thread bores,
bolts, nuts and mating surfaces are clean.
lnstall bushing end of control arm to subframe, using wash-
ers on both sides of bolt and a new self-loclting nut. Do not
tighten nut at this time.
lnstall control arm ball joint to steering knuckle, using new
self-locking nut. Tighten fully.
- Slide strut back into position and tighten strut pinch bolt fully.
- Install wheel and lower car.
- Load car to normal loaded position as described under Ride
height. See
300 Suspension, Steering and Brakes-Gen-
eral. Bounce suspension a few times.
- With car on ground and loaded, tighten control arm bushing
through-bolt.
Tightening torques
Control arm to steering knuckle 80 Nm
(59 ft-lb)
Control arm to
subframe 78 Nm (58 ft-lb)
Road wheel to hub
120
f 10 Nm (89 +7 ft-lb)
Stabilizer bar
link to stabilizer bar
59 Nm (44 fl-lb)
Strut pinch bolt
81 Nm (60 it-lb)

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I Front Suspension
Tension strut, removing
and installing
- Raise car and remove wheel.
WARNING-
Make sure that the car is firmly supported on jack stands de-
signed for the purpose. Place jack stands underneath struc-
tural chassis points. Do not place
jack stands under
suspension parts.
- Remove engine splash shield
6-cylinder models: Remove
brake cooling duct.
V-8 models: Detach stabilizer bar from front subframe.
Mark installation position of strut tube (arrow) at steering
ltnuckle pinch collar.
NOJE-
* The strut tube installation position is marlted on factory
strut tubes:
L for left and R for right.
* Marlting the strut tube is not necessary if factory marks (L
or R) are still visible.
CAUJION-
Use paint, not a scribe tool, to mark location of strut tube. 1
4 Counterhold strut tube pinch bolt (arrow) while loosening
nut.

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31 0-1 7
Front ~uspensionl
< Spread steering knuckle pinch collar with BMW special tool
31 2 200 to release strut tube.
- Pull steering knuckle down so strut tube slides up farenough
to gain better access to tension strut or tension strut nut.
4 Unscrew ball joint nut (arrow) from steering knuckle. Use
BMW special tool
31 2 240 to remove ball joint from steering
Iknucltle.
CAUTION--
Tale care not to damage the balljoint threads if the tension
strut
is to be reused.
- Remove through-bolt attaching tension strut to subframe.
- When installing tension strut, make sure all thread bores,
bolts, nuts and mating
suriaces are clean.
- Install bushing end of tension strut to subframe using wash-
ers on both sides of bolt and a new self-locking nut. Do not
tighten nut at this time.
- Install tension strut ball joint to steering knuckle using new
self-locking nut. Tighten fully.
- Slide strut back into position and tighten strut pinch bolt fully.
- Install wheel and lower car.
- Load car to normal loaded position as described under Ride
height. See
300 Suspension, Steering and Brakes-Gen-
eral. Bounce suspension a few times.
- With car on ground and loaded, tighten tension strut bushing
through-bolt.
Tightening torques Road
wheel to hub 120-i-10 Nm (89+7ft-lb)
Stabilizer bar to subframe 24 Nm (1 8 ft-lb)
Tension strut to steering
knucltle
80 Nm (59 ft-lb)
Tension strut
to subframe 110 Nm (81 ft-lb)
81 Nm (60 it-lb)
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