front strut BMW 540i 1998 E39 Owner's Manual

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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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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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Front Suspension
4 Remove ABS pulse sensor mounting bolts (arrows) and pull
sensor from housing.
- Detach stabilizer bar link from stabilizer bar.
4 6-cylinder models: Remove tie rod outer end nut. Use BMW
special tool
31 2 240 or equivalent to press tie rod end off
steering arm.
4 Mark installalion position of strut tube (arrow) at steering
knuckle pinch collar.
NOTE-
The strut tube installation position is marked on factory strut
tubes:
L for left and R for right.
CAUTION-
Use paint, not a scribe tool, to mark location of strut tube.

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31 0-20
Front Suspension
Counterhold strut tube
nut. pinch
bolt (arrow) while loosening
4 Spread steering ltnuckle pinch collar with BMW special tool
31 2 200 to release strut tube.
- Pull steering knuckle down so that strut tube slides up far
enough to gain access to wheel bearing hub mounting bolts.
Carefully pry out dust cover on back side of bearing while
noting location
(arrow) of cover.

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31 0-21
Front Suspension
4 Remove four bearing hub mounting bolts (arrows) and tap
hub assembly out of steering knuckle.
4 Before installing new wheel bearing and hub assembly, be
sure hub and steering knuckle sealing surfaces are free of
dirt and grease.
- Installation is reverse of removal.
Replace hub mounting bolts.
Use new self-locking nuts at steering tie rod and stabilizer
link.
Tightening
torques
Road wheel lugs to hub 120i-10 Nm (89i-7ft-lb)
Stabilizer link to stabilizer bar
Steering tie rod to steering
ltnuckle
Tension strut to steering
knucltie
Wheel bearing hub to steering
Itnucltle (replace bolts)
65 Nm (48 ft-lb)
65
Nm (48 it-lb)
80 Nm (59 ft-lb)
1
lo Nm (81 ft-lb)

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31 0-22
I Front Suspension
Stabilizer bar, removing and installing
On E39 models the front stabilizer bar links attach to the strut
assemblies.
- Raise car and support safely.
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 jaclc stands under
suspension parts.
< Remove slaol zer bar connecring I nk rnounl ng nLts (A) from
r~glit and eft s~des of slaol lzer bar C~~nIerhol~ ball ]olnl (6)
with flat wrench
NOTE-
Use a thin wrench to counterhold shaft of stabilizer bar link
ball joint while removing mounting nut.
< Remove stabilizer bar anchor bushing nuts (arrows) on right
and left sides and remove bar.
- Installation is the reverse of removal, noting the following.
Use new self-locking nuts on stabilizer bar links.
Installation of stabilizer bar is easiest with car level (front
wheels at the same height).
Tightening torques Stabilizer bar to stabilizer link
59 Nm (44 ft-lb)
Stabilizer anchor to subframe 22 Nm (16 ft-lb)

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Steerina and Wheel ~lianmentl
Proper handling, stability and driving ease depend upon the
correct alignment of all four wheels. The front axle is aligned
in relation to the rear axle, then the front wheels are aligned in
relation to one another. This is known as a four-wheel or
thrust-axis alignment.
Front and rear alignment specification are given in tables at
the end of this repair group.
BMW E39 cars use a sophisticated multi-link suspension at
the front and rear of the car. Proper alignment requires com-
puterized alignment equipment.
Camber
Front wheel camber is set at the factory and cannot be adjust-
ed. Rear wheel camber is fully adjustable.
Always set rear camber before adjusting toe
Before making rear camber adjustment, install a new rear
control arm mounting nut
(arrow) and tighten.
- Loosen mounting nut one-half to one full turn.
Using eccentric bolt, adjust camber to factory settings.
Tighten nut only after car has been lowered to ground and
suspension has settled.
Tighten nut while counterholding adjustment bolt.
Tightening torque
Camber adjusting nut (rear)
MI2 (sedan)
- MI4 (Sport Wagon)
115 Nm (85 ft-lb)
174 Nm (128 ft-lb)
Caster
Front and rear caster are fixed by the design of the car and
deviations are usually the result of worn or damaged suspen-
sion or body parts.
- Check front suspension arms and bushings for wear, dam-
age and deformation if front caster problems are present.
- Check rear axle subfrarne and traction struts if rear caster
problems are present.

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320-34
I Steerins and Wheel Alignment
Front toe and toe difference angle
Toe is the difference in the distance between the front of the
front wheels and the rear of the front wheels. It is adjusted by
altering the length of the tie rods.
Toe difference angle determines the progressively different
paths taken by the front wheels as the car is turning. In
V-8
models, it is set by the pitman arm adjustment, but depends
on accurate setting of the toe.
Toe adjustments should only be made on specialized align-
ment equipment and only with the car in normal loaded posi-
tion, described below.
- Set front wheel toe at tie rod ends:
4 6-cylinder models: Loosen tie rod lock nut (A).
Adjust toe by turning inner tie rod (B) to change length
- V-8 models: Loosen left and right tie rod clamp bolts.
Adjust toe by turning inner tie rod to change length.
NOTE-
* Steering rack or steering gearbox can be centered by
aligning centering mark on steering shaft
with lug on steer-
ing rack.
To keep steering wheel centered, adjust both tie rods equal
amounts.
&cylinder models: Make sure the rubber boot on the rack
moves freely on the tie rod and does not become twisted.
Tightening torques
Tie rod clamp bolt
Tie rod collar
nut
27 Nm (20 ft-lb)
45 Nm (33 A-lb)
Rear toe
To adjust rear wheel toe, turn eccentric inner mounting bolt in
upper front control arm (traction strut).
NOTE-
Always adjust rear camber first.
- Before making toe adjustment, install new
mounting nut and tighten.
- Loosen nut one-half to one full turn.
4 Turn eccentric bolt (arrow) to adjust toe. rear
control arm

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Steering and Wheel Alignment
- Tighten nut while counterholding adjusting bolt,
- Tighten nut only after car has been lowered to ground and
suspension has settled.
Preparing for alignment
- The following conditions are necessary prior to wheel align-
ment:
Correct wheels and tires are installed, in good condition,
and are at the correct inflation pressures.
All steering and suspension parts and bushings are un-
damaged and show no signs of abnormal wear. Wheel
bearings are in good condition.
Ride height is in accordance with specifications. See
300
Suspension, Steering and Brakes-General.
Car is in normal loaded position. See below.
* Cars with air suspension: Remove air suspension power
fuse.
Normal loaded position
Each front seat
68 Kg (I50 lb)
Center of rear seat
Trunlc
Fuel tank
68 Kg (150 lb)
21 Kg (46 lb)
Full
Alignment specifications tables
In the alignment specification tables that follow, reference is
made to the various types of suspension used in
E39 cars.
The type of suspension can be identified by loolting at the la-
bel on the front strut tube.
Identifying symbol
None
Solid circle
Solid triangle
M5
Circle
Triangle Version
Standard suspension
Sports
suspension
Sports suspension
M sport package
Standard suspension
Sports suspension Model
Sedan
6-cylinder sedan
V-8 sedan
V-8 sedan
Touring (Sport Wagon)
Touring (Sport Wagon)

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330 Rear Suspension
General . . . . . . . . . . . . . . . . . . . . . . . . . . . ,330-2
Special tools . . . . . . . . . . . . . . . . . . . . . . . . ,330-2
Rear suspension variations . . . . . . . . . . . . ,330-4
Rear Struts and Springs
(sedan models)
. . . . . . . . . . . . . . . . . . . . ,330-5
Rear strut assembly, removing
and installing
. . . . . . . . . . . . . . . . . . . . . . . ,330-5
Rear strut assembly, disassembling
and assembling
. . . . . . . . . . . . . . . . . . . . . ,330-7
Rear Shock Absorbers and
Springs (Sport Wagon models)
. . . . . ,330-9
Rear shock absorber, removing
and installing
. . . . . . . . . . . . . . . . . . . . . . . ,330-9
Coil spring, removing and installing . . . . . ,330-1 1
Air spring, removing and installing
. . . . . . ,330-12
Rear Suspension Arms,
Subframe and Bushings . . . . . . . . . . ,330-13
Rear suspension arm components . . . . . . ,330-1 3
Swing arm, removing and installing (sedan models)
. . . . . . . . . . . . . . . . . . . . . ,330-1 4
Swing arm, removing and installing (Sport Wagon models)
. . . . . . . . . . . . . . . ,330-16
Swing arm ball joint, replacing . . . . . . . . . ,330-1 9
Upper rear control arm, removing
and installing (sedan models)
. . . . . . . . . . .330-22
Upper rear control arm, removing
and installing (Sport Wagon models)
. . . . .330-23
Upper front control arm (traction strut),
removing and installing
. . . . . . . . . . . . . . . ,330-25
Rear axle assembly, removing and
installing (sedan models)
. . . . . . . . . . . . . ,330-26
Rear axle assembly, removing and
installing (Sport Wagon models)
. . . . . . . ,330-28
Rear subframe mounting bushings,
removing and installing
. . . . . . . . . . . . . . . .330-31
Rear Wheel Bearings . . . . . . . . . . .
Rear wheel bearing carrier, removing
and installing (sedan models)
. . . . . . .
Rear wheel bearing carrier, removing
and installing (Sport Wagon models)
. .
Rear wheel bearing, replacing . . . . . . .
Rear Stabilizer Bar
Stabilizer bar, removing and installing .
Stabilizer bar link, removing
and installing
. . . . . . . . . . . . . . . . . . . .
Electronic Height Control (EHC)
Component Replacement
. . . . . . .
Electronic height control (EHC)
components
.....................
Air compressor pump relay, removing
and installing
. . . . . . . . . . . . . . . . . . . .
EHC control module, removing
and installing
. . . . . . . . . . . . . . . . . . . .
Air supply unit, removing and installing
Ride height sensor, removing
and installing
. . . . . . . . . . . . . . . . . . . .