ECT BMW 528i 1998 E39 Workshop Manual

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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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Front ~us~ensionl
Spread steering knuckle slot in
tool
31 2 200.
pinch collarwith BMW special
4 Worlting in engine compartment at strut tower:
- If applicable, disconnect plug connector at top of strut for
Electronic Damper Control and remove cap from cable.
Remove upper strut bearing mounting fasteners
(arrows).
WARNING-
Do not remove centerstrut retaining nut.
4 Use lever to push down on wheel hub. Tilt strut outward
NOTE-
Use masking tape to protect fender arch from possible dam-
age.

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31 0-9
Front Suspension
Front strut assembly
components
(6-cylinder models)
1. Cap
2. Upper strut self-locking nut
3. Washer
4. Strut bearing reinforcement
5. Strut mount self-locking nut
6. Upper strut mount
7. Dust protector collar
8. Spacer
9. Upper spring seat
10. Spacer
11. Upper spring pad
12. Coil spring
13. Rubber stop
14. Dust boot
15. Lower strut pad
16. Strut with lower spring seat
Front strut assembly, disassembling
and assembling
Replacing the strut, upper strut mount or spring requires that
the strut assembly first be removed from the car
and disas-
sembled. For a guide to parts used during component re-
placement, see the accompanying diagram.
NOTE-
Illustration shows components ior 6-cylinder models (525i,
528i, 530;). V-8 models (540i) are similar but not identical.

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31 0-1 0
Front Suspension
4 Clamp spring compressor (BMW special tool 31 3 340 or
equivalent) in shop vise.
WARNING-
* Do not attempt to disassemble the strut assembly without
a spring compressor designed specifically for this job.
Prior to each use,
checlc special tool for functionality.
Do not use a damaged tool.
Do not make any modifications to tool. Use correct size spring retainers when compressing
coil spring.
I When assembling BMW spring compressor (special
tool
31 3 340), make sure spring retainerplates are felt
and heard snapping into place. Check seating of spring
retainers carefully.
Position coil spring between spring holders so that
3 coils lie
between spring holders
(arrows). Compress spring.
WARNING -
When tensioned, the spring coils must rest completely in
the spring holder recess.
Never tighten or loosen spring compressor with an im-
pact tool.
Only tighten down the coil springs until stress on the
thrust bearing is relieved.
a Only loosen strut nut if spring coils are completely in-
serted in the spring holder grooves. If
necessarx loos-
en compressor, reposition and recompress.
Use
BMW special tool 31 2 21 0 or equivalent to remove strut
nut. Counterhold strut shaft using
6 mm Allen wrench.
CAUTION-
Do not remove strut nut with impact tool.
Remove upper strut bearing and related components.
If a new coil spring is being installed, relieve tension on
spring compressor and remove coil spring.
Check strut dust boot, rubber stop and spring pads. Replace
as necessary.
Replace strut, upper strut mount or spring, as needed

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Front Suspension
/ Front strut top mount assembly
< Replace springs in matched pairs only. BMW ID number is
stamped near end
(A).
4 Assembly is reverse of disassembly, noting the following:
Use a new upper strut self-loclting nut
(A). Tighten nut
fully before releasing spring compressor.
CAUTION-
Do not tighten strut nut with impact tool.
NOTE-
illustration shows components for 6-cylinder models (5257,
528i, 5300. V-8 models (5400 are similar but not identical.
4 Be sure upper and lower spring pads (arrows) are correctly
installed to spring seats before releasing spring compressor.
Release spring compressor carefully and evenly, allowing
spring to expand slowly.
Have car professionally aligned when job is complete.
Tightening torques Upper strut mount to strut shaft
64 Nm (47 ft-lb)
Strut mount to strut tower (ME) 24 Nrn (18 fi-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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31 0-1 8
I~ront Suspension Tension strut bushing, replacing
- Raise car and remove wheel.
WARNING-
Make sure that the caris 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 tension strut from car as described earlier.
- Using a service press and appropriate press tools (BMW
special tools 31 2 26112621263 or equivalent), press bushing
out of tension strut.
4 Clean bushing bore and press in new bushing while aligning
mark on bushing with
rnarlt on tension strut (arrows).
CAUTION-
To avoid damaging the new bushing, press only on the outer
steel sleeve during installation.
- Press bushing in so it protrudes equally from both sides of
tension strut.
- Install tension strut as described earlier.
CAUTION-
Tighten the tension strut bushing through-bolt to its final
torque only with car on the ground and the suspension nor-
mally loaded as described earlier.
The front wheel bearings are permanently sealed and require
no maintenance. The bearing is integral with the wheel hub.
The wheel bearing and hub assembly is bolted to the steering
knuckle.
- 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
susoension Darts.
- Unbolt brake caliper and hang to side with stiff wire. Do not
disconnect bralte hose. Remove bralte disc. See
340
Brakes.

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I Steerina and Wheel Alianment
Steering
system
Two types of steering gear are used in the E39 series models.
6-cylinder
(5251, 528i and 530i) models are equipped with
rack and pinion steering. The steering rack is mounted to
an aluminum subframe.
V-8
(540i) models are equipped with a recirculating ball
and nut steering gearbox mounted to a steel subframe.
At low speeds, maximum power assist is provided to ease
parking and city driving. At high speeds, assist is reduced to
ensure stability. The power steering system varies assist
based on engine speed.
Power boost for the steering is provided by an engine-driven
hydraulic pump. A hydraulic control valve is used to control
boost pressure.
The steering wheel connects to the steering gear via an ad-
justable steering column which incorporates a rubber cou-
pling ("guibo") to dampen vibration and noise.
Power steering fluid is supplied from the fluid
reservoir to the
pump and to the steering gear via rubberlmetal hoses.
The return line from the steering gear to the
reservoir loops
into the airstream in front of the radiator and connects to the
steering fluid cooler. The fluid cooler is attached to a cassette
which also includes cooling coils for engine oil, transmission
fluid and AIC condenser.
The steering gear requires no maintenance other than align-
ment and periodic inspection for worn components. Inspect
rubber rack boots
(rack and pinion system) and tie-rod end
boots periodically for tears or damage. Replace
if necessary.
-
NOTE-
The airbag system is traditionally referred to as Supplemen-
tal Restraint System (SRS). The
BMW versfon of SRS used
m the E39 models is known as the Multiple Restraint System - (MRS). - -

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Steering and Wheel Alignment
Steering system warnings and cautions
WARNING -
The BMW airbag system is complex. Special precautions
must be observed when servicing the system. Serious in-
jury may result if system service is attempted by persons
unfamiliar with the BMW
airbag system and its approved
service procedures. BMW specifies that all inspection and
service should be
peiformed by an authorized BMW deal-
e,:
The BMW E39 is equipped with an airbag mounted in
the steering wheel. The
airbag is an explosive device
and should be treated with extreme caution. Always fol-
low the
airbag removal procedure as outlined in 721
Airbag System (SRS).
BMW airbags are equipped with a bacli-up power sup-
ply inside the
airbag control module. A 5 second wait-
ing period should be observed after the battery cable
has been disconnected. This will allow the reserve
power supply to discharge.
Do not reuse self-locking nuts. They are designed to
be used only once and may fail if reused. Always re-
place them with new locliing nuts.
* Do not install bolts and nuts coated with undercoating
wax, as correct tightening torque cannot be assured.
Always clean the threads with solvent before installa-
tion, or install new parts.
Do not attempt to weld or straighten any steering com-
ponents. Always replace damagedparts.
CAUTION--
- Some E39 models are equipped with aluminum suspen.
sion components. The following 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-
tles. Only use brushes with stainless steel bristles.
Do
not expose to flying sparks from grindinghutting op-
erations.
Do not subject to steel welding splashes.
* Do not expose to temperatures over 80% (176°F).
even for short periods. Temperatures in painting iacili-
ties are not a problem.