1991 BMW 5 SERIES Check control

and cause the system to malfunction. If
the ABS wiring harness is damaged in any
way, it must be renewed.
Caution: Make sure the ignition is
turned off before unplugging or
re-making any electrical
connections.
Diagnosis and repair
If the dashboard warning light comes on
and stays on while the vehicle is in operation,
the ABS system requires attention. Although
special electronic ABS diagnostic testing
tools are necessary to properly diagnose the
system, you can perform a few preliminary
checks before taking the vehicle to a dealer
service department.
a) Check the brake fluid level in the
reservoir.
b) Verify that the electronic control unit
connectors are securely connected.
c) Check the electrical connectors at the
hydraulic control unit.
d) Check the fuses.
e) Follow the wiring harness to each front
and rear wheel, and verify that all
connections are secure and that the
wiring is undamaged.
If the above preliminary checks do not
rectify the problem, the vehicle should bediagnosed by a dealer service department.
Due to the complex nature of this system, all
actual repair work must be done by a dealer
service department.
3 Disc brake pads- renewal
2
Warning: Disc brake pads must
be renewed on both front wheels
or both rear wheels at the same
time - NEVER renew the pads on
only one wheel. Also, the dust created by
the brake system may contain asbestos,
which is harmful to your health. Never
blow it out with compressed air, and don’t
inhale any of it. An approved filtering mask
should be worn when working on the
brakes. Do not, under any circumstances,
use petroleum-based solvents to clean
brake parts. Use brake system cleaner
only! When servicing the disc brakes, use
only original-equipment or high-quality
brand-name pads.
Warning: Brake fluid is
poisonous. It is also an effective
paint stripper. Refer to the
warning at the start of Section 16.
Note:This procedure applies to both the front
and rear disc brakes.
1Remove the cap(s) from the brake fluid
reservoir, and syphon off about two-thirds of
the fluid from the reservoir. Failing to do thiscould result in the reservoir overflowing when
the caliper pistons are pressed back into their
bores.
2Loosen the wheel bolts, raise the front or
rear of the vehicle and support it securely on
axle stands.
3Remove the front or rear wheels, as
applicable. Work on one brake assembly at a
time, using the assembled brake for reference
if necessary.
4Inspect the brake disc carefully as outlined
in Section 5. If machining is necessary, follow
the information in that Section to remove the
disc, at which time the pads can be removed
from the calipers as well.
5Follow the accompanying photos,
beginning with illustration 3.5a, for the pad
removal procedure. Be sure to stay in order,
and read the caption under each illustration.
Note 1:Different types of front calipers are
used on 3 and 5-Series models. Illustrations
3.5a to 3.5e are for the front calipers on 3-
Series models.Illustrations 3.5f to 3.5m are
for the front calipers on 5-Series models.
There’s no photo sequence for rear calipers;
although slightly different in size, they’re
identical in design to the front brake calipers
used on 5-Series models.Note 2: Some
models may have different numbers and types
of anti-squeal shims and other hardware than
what is shown in this Chapter. It’s best to note
how the hardware is fitted on the vehicle
before dismantling, so you can duplicate it on
reassembly.
Braking system 9•3
3.5c Hold the guide pins while loosening
the caliper mounting bolts (3-Series)3.5b Unplug the electrical connector for
the brake pad wear sensor (3-Series)
3.5a On 3-Series models, unscrew the
caliper mounting bolts (left arrows); right
arrows point to the caliper bracket bolts,
which should only be removed if you’re
removing the brake disc
3.5f On 5-Series models, unplug the
electrical connector for the brake pad
wear sensor3.5e Remove the outer brake pad
(3-Series) - to fit the new pads, reverse the
removal procedure
3.5d Remove the caliper, brake pad wear
sensor and inner pad all at the same time
(3-Series), then refit the inner pad on the
piston and press the piston fully into the
bore with a C-clamp
9

friction surfaces of the brake shoes or
drums.
12Make sure the adjuster assembly is
properly engaged with its respective notch in
the handbrake lever.
13When refitting the automatic adjustment
mechanism, fit the lever on the shoe first (see
illustration), then hook the lower end of the
spring onto the lever and the upper end into
its hole in the front shoe (see illustration).
14When you’re done, the brake assembly
should look like this (see illustration). Now
proceed to the other brake.
15When you’re done with both brakes, refit
the brake drums.
16If the wheel cylinder was renewed (see
Note 2), bleed the hydraulic system as
described in Section 16.
17Depress the brake pedal repeatedly to
actuate the self-adjusting mechanism. A
clicking sound will be heard from the brake
drums as the adjusters take up the slack.
18Check the handbrake adjustment (Sec-
tion 11).
19Refit the wheels and bolts. Lower the
vehicle to the ground, and tighten the wheel
bolts to the torque listed in the Chapter 1
Specifications. Check the operation of the
brakes carefully before driving the vehicle in
traffic.
7 Master cylinder-
removal and refitting
3
Warning: Brake fluid is
poisonous. It is also an effective
paint stripper. Refer to the
warning at the start of Section 16.
Note: Although master cylinder parts and
overhaul kits are available for most models, we
recommend fitting a new or overhauled
master cylinder complete. It will take you more
time to overhaul the master cylinder than to
renew it, and you can’t even determine
whether the master cylinder is in good enough
condition to overhaul it until you have
dismantled it. You may very well find that itcan’t be overhauled because of its internal
condition.
Removal
1The master cylinder is connected to the
brake vacuum servo, and both are attached to
the bulkhead, located on the left-hand side of
the engine compartment (see illustration).
2Remove as much fluid as you can from the
reservoir with a syringe.
3Place rags under the line fittings, and
prepare caps or plastic bags to cover the
ends of the lines once they are disconnected.
Caution: Brake fluid will damage
paint. Cover all body parts, and
be careful not to spill fluid during
this procedure.
4Loosen the union nuts at the ends of the
brake lines where they enter the master
cylinder. To prevent rounding off the flats on
these nuts, a split ring (“brake”) spanner,
which wraps around the nut, should be used.
5Pull the brake lines away from the master
cylinder slightly, and plug the ends to prevent
dirt contamination and further fluid loss.
6Disconnect any electrical connectors at the
master cylinder, then remove the nutsattaching the master cylinder to the brake
servo. Pull the master cylinder off the studs,
and lift it out of the engine compartment.
Again, be careful not to spill fluid as this is
done. Discard the old O-ring (see illustration)
between the master cylinder and the servo
unit.
Warning: The O-ring should
always be renewed. A faulty O-
ring can cause a vacuum leak,
which can reduce braking performance
and cause an erratic idle.
Bleeding procedure
7Before fitting a new or overhauled master
cylinder, it should be bled on the bench.
Because it will be necessary to apply pressure
to the master cylinder piston and, at the same
time, control flow from the brake line outlets, it
is recommended that the master cylinder be
mounted in a vice. Use a vice with protected
jaws, and don’t clamp the vice too tightly, or
the master cylinder body might crack.
8Insert threaded plugs into the brake line
outlet holes. Tighten them down so that there
will be no air leakage past them, but not so
tight that they cannot be easily loosened.
9Fill the reservoir with brake fluid of the
recommended type (see “Lubricants, fluids
and capacities” in Chapter 1).
10Remove one plug, and push the piston
assembly into the master cylinder bore to
Braking system 9•9
6.14 When you get everything back
together, this is how it
should look! 6.13b . . . then hook the lower end of the
spring onto the lever as shown; stretch the
spring, and hook the upper end into its
hole in the handbrake shoe6.13a Refit the automatic adjuster lever
first - make sure it’s properly engaged with
the notch in the front end of the
adjuster mechanism . . .
7.6 Always renew the O-ring (1) - groove
arrowed - between the master cylinder and
the brake servo
7.1 To remove the master cylinder, unplug
the electrical connector (top arrow),
disconnect the brake fluid hydraulic line
fittings (lower right arrow, other fitting not
visible in this photo) and remove the two
master cylinder mounting nuts (lower left
arrow, other nut not visible in this photo) -
5-Series master cylinder shown, 3-Series
similar
9

10
General
Power steering fluid type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1
Tyres
Tyre sizes
3-Series, E30
316 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175/70x14
316i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175/70x14, 195/65x14
318i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175/70x14
320i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195/65x14
325i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195/65x14, 200/60x356, 205/55x15
5-Series, E28 (“old-shape”)
518 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175x14
518i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175x14
525i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175x14, 195/70x14
528i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195/70x14
535i and M535i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220/55x390
5-Series, E34 (“new-shape”)
518i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195/65x15
520i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195/65x15, 225/60x15
525i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195/65x15, 205/65x15, 225/65x15
530i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205/65x15, 225/60x15
535i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225/60x15, 240/45x415
Tyre pressures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1 Specifications
Chapter 10 Suspension and steering systems
Balljoints - check and renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Control arm (3-Series) - inspection, removal and refitting,
and bush renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Control and thrust arms (5-Series) - inspection, removal and
refitting, and bush renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Front anti-roll bar - removal and refitting . . . . . . . . . . . . . . . . . . . . . 2
Front hub and wheel bearing assembly - removal and refitting . . . . 8
Front strut assembly - removal and refitting . . . . . . . . . . . . . . . . . . . 5
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Power steering fluid level check . . . . . . . . . . . . . . . . See Chapter 1
Power steering pump - removal and refitting . . . . . . . . . . . . . . . . . . 22
Power steering system - bleeding . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Rack-and-pinion steering gear (3-Series) - removal and refitting . . . 19
Rear anti-roll bar - removal and refitting . . . . . . . . . . . . . . . . . . . . . . 12
Rear coil springs (3-Series) - removal and refitting . . . . . . . . . . . . . . 10
Rear shock absorbers (3-Series) - removal and refitting . . . . . . . . . 9
Rear shock absorber/coil spring assembly (5-Series) - removal
and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Rear trailing arms (3-Series) - removal and refitting . . . . . . . . . . . . . 13
Rear trailing arms (5-Series) - removal and refitting . . . . . . . . . . . . . 14
Rear wheel bearings - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Steering and suspension check . . . . . . . . . . . . . . . . . See Chapter 1
Steering box (5-Series) - removal and refitting . . . . . . . . . . . . . . . . . 21
Steering gear boots (3-Series) - renewal . . . . . . . . . . . . . . . . . . . . . . 18
Steering linkage (5-Series) - inspection, removal and
refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Steering system - general information . . . . . . . . . . . . . . . . . . . . . . . 16
Steering wheel - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . 24
Strut or shock absorber/coil spring - renewal . . . . . . . . . . . . . . . . . . 6
Suspension and steering checks . . . . . . . . . . . . . . . . See Chapter 1
Track rod ends - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . 17
Tyre and tyre pressure checks . . . . . . . . . . . . . . . . . See Chapter 1
Tyre rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1
Wheel alignment - general information . . . . . . . . . . . . . . . . . . . . . . . 26
Wheels and tyres - general information . . . . . . . . . . . . . . . . . . . . . . 25
10•1
Easy,suitable for
novice with little
experienceFairly easy,suitable
for beginner with
some experienceFairly difficult,
suitable for competent
DIY mechanic
Difficult,suitable for
experienced DIY
mechanicVery difficult,
suitable for expert
DIY or professional
Degrees of difficulty
Specifications Contents

2 Front anti-roll bar-
removal and refitting
2
Removal
1Raise the front of the vehicle, and support it
securely on axle stands.
2If you’re removing or renewing the anti-roll
bar itself, or disconnecting the bar to renew
the strut assembly on a 3-Series model,
disconnect it from the anti-roll bar links (see
illustrations). If you’re renewing the strut
assembly on a 5-Series model, disconnect the
anti-roll bar link from the strut housing.
3On 3-Series models, disconnect the left
control arm rubber bush from the underbody
(see Section 3).
4Remove the bolts from the anti-roll bar
brackets which attach the anti-roll bar to the
subframe (see illustration).
5Remove the anti-roll bar from the vehicle.
Where necessary, separate the anti-roll bar
from the strut bar bracket.
Refitting
6Refitting is the reverse of the removal
procedure. Be sure to tighten all nuts and
bolts to the torques listed in this Chapter’s
Specifications.
3 Control arm (3-Series)-
inspection, removal and
refitting, and bush renewal
3
Inspection
1Raise the front end of the vehicle, and
support it securely on axle stands.
2Grip the top and bottom of each balljoint
with a large pair of water pump (“parrot jaw”)
pliers, and squeeze to check for free play.
Alternatively, insert a lever or large
screwdriver between the control arm and the
subframe or strut housing. If there’s any free
play, renew the control arm (the balljoints
can’t be renewed separately).
3Inspect the rubber bush. If it’s cracked, dry,
torn or otherwise deteriorated, renew it (see
below).
Bush renewal
Note:Rubber bushes should always be
renewed in pairs. Make sure both new bushes
have the same markings (indicating they’re
manufactured by the same firm).
4Remove the two bolts (see illustration)which
attach the bush bracket to the underbody.
5Using a puller, remove the bracket andbush from the end of the control arm. If the
puller slips on the end of the control arm,
centre-punch the control arm to give the
puller bolt a place to seat.
6Note the orientation of the old bush. This is
exactly how the new bush should be
orientated when it’s fitted. Press the old
rubber bush out of the bracket, or have it
pressed out by an engineering works.
7Coat the end of the control arm with BMW’s
special lubricant (Part No. 81 22 9 407 284),
and press the new bush and bracket onto the
arm - or have it pressed on at an engineering
works - all the way to the stop.
Caution: Don’t try to use any
other type of lubricant;
30 minutes after it’s applied, this
lubricant loses its properties and
the bush is permanently located in its
proper position. Make sure the new bush
is pressed on so it’s orientated exactly the
same way as the old bush.
8Refit the bracket bolts and tighten them to
the torque listed in this Chapter’s Specifi-
cations.
9Lower the vehicle, and leave it at rest for at
least 30 minutes (this will give the special
lubricant time to dry).
Control arm removal and
refitting
Note:If either balljoint is worn or damaged,
the only way to renew it is to renew the control
arm. If you’re fitting a new control arm, a new
bush must also be fitted. The old bush can’t
be removed from the old control arm and re-
used in the new control arm.
10Loosen but do not remove the wheel
bolts, raise the front of the vehicle and
support it on axle stands. Remove the wheel
bolts and the front wheel.
11Remove the two bolts which attach the
rubber bush bracket to the underbody (see
illustration 3.4).
12Remove the nut which secures the control
arm balljoint to the subframe, and remove the
balljoint stud from the subframe. Note:It may
be necessary to use a balljoint separator to
separate the balljoint from the subframe (see
illustration), but take care not to damage the
10•4 Suspension and steering systems
3.12 Remove the self-locking nut from the
balljoint stud protruding through the top of
the subframe (not shown in this photo, but
it’s directly above the balljoint) and
separate the balljoint from the subframe.
Try not to damage the dust boot
3.4 Remove the two bolts (arrowed)
securing the bush bracket to the
underbody
2.4 Remove the bolts (arrowed) from the
anti-roll bar brackets to detach the anti-
roll bar from the subframe (3-Series model
shown, 5-series similar)2.2b On 5-Series models, remove the nut
(arrowed) securing the anti-roll bar to the
connecting link (left side shown, right side
similar)2.2a On 3-Series models, remove the nut
(upper arrow) securing the anti-roll bar to
the upper end of the connecting link (left
side shown, right side similar). If a new
control arm is being fitted, remove the
lower nut (lower arrow) and disconnect the
link assembly and bracket from the arm

dust boot. If the boot does become damaged
(and you’re refitting the same control arm and
balljoint), be sure to fit a new boot.
13Unscrew the nut which secures the outer
control arm balljoint to the steering knuckle
(see illustration)and detach the balljoint stud
from the knuckle (see illustration). Ideally you
should use a purpose-made balljoint
separator tool for this job. Using a hammer is
OK if you’re going to fit new parts anyway, but
is not recommended if you’re planning to re-
use parts.
14Remove the control arm.15If you’re renewing the control arm, you’ll
have to fit a new bush (see above). The old
bush can’t be removed re-used in another
control arm.
16Refitting is the reverse of removal. Be sure
to use new self-locking nuts on the balljoint
studs and tighten them, and the bush bracket
bolts, to the torques listed in this Chapter’s
Specifications.
17When you’re finished, have the front
wheel alignment checked by a dealer service
department or qualified garage.
4 Control and thrust arms
(5-Series)- inspection, removal
and refitting and bush renewal
3
Inspection
1Inspect the thrust arm rubber bush (see
illustration 4.6b). If the bush is cracked, torn
or otherwise deteriorated, renew it. The
control arm bush can’t be inspected until the
control arm is removed.
2Raise the vehicle and place it securely on
axle stands.
3To inspect the control arm and thrust arm
balljoints for wear, grip the top and bottom of
each balljoint with a large pair of water pump
(“parrot jaw”) pliers, and try to squeeze them.
Alternatively, use a lever or large screwdriver
to move them up and down. If there’s any free
play, renew the control arm or thrust arm. The
balljoints can’t be renewed separately.
Removal
Note:If a balljoint is worn or damaged, the
only way to renew it is to renew the control
arm or thrust arm. If you’re fitting a new
control arm or thrust arm, a new bush must
also be fitted. The old bush can’t be removed
from the old control arm or thrust arm and re-
used in the new arm.
4Loosen the wheel bolts, raise the vehicle
and support it securely on axle stands.
Remove the wheel.
5If you’re removing the control arm, remove
the three bolts from the steering arm (see
illustration)and separate the strut assembly
from the arm.
6Remove the nut and the through-bolt that
secure the control arm or thrust arm rear
mounting (see illustrations).
7Remove the nut from the balljoint (see
illustration). Support the steering arm and
separate the balljoint from the steering arm
(see illustrations). Ideally you should use a
purpose-made balljoint separator tool for this
job. Using a hammer is OK if you’re going to
fit new parts anyway, but is not recommended
if you’re planning to re-use parts.
Suspension and steering systems 10•5
4.5 If you’re removing the control arm,
remove the three bolts (arrowed) from the
steering arm, and separate the strut
assembly from the arm
3.13b . . . give the steering knuckle a few
sharp knocks with a hammer to release
the balljoint stud from the strut housing,
and remove the control arm3.13a Remove the self-locking nut from
the balljoint stud which attaches the outer
end of the control arm to the steering
knuckle. If you don’t have a balljoint
separator tool . . .
4.7b You can separate the thrust arm
balljoint from the steering arm with a
puller . . .
4.6a If you’re removing the control arm,
remove the self-locking nut and the
through-bolt (arrowed) that attach the
inner end of the arm to the vehicle
4.7a Remove the self-locking nut (control
arm nut, left arrow; thrust arm nut, right
arrow) from the balljoint, then support the
steering arm, and press or knock the
balljoint out of the steering arm
4.6b If you’re removing the thrust arm,
remove the nut and bolt (arrowed) that
secure the rear end of the arm
10

Bush inspection and renewal
8If the bush is cracked, torn or otherwise
deteriorated, take the arm to a BMW dealer
service department or an engineering works,
and have it pressed out and a new bush
pressed in. Bushes should always be renewed
in pairs (a new bush should be fitted in each
arm, and both bushes should have the same
manufacturer markings). If you’re fitting a new
thrust arm bush, make sure it’s correctly
orientated (see illustration).
Refitting
9Refitting is the reverse of removal. Be sure
to use new self-locking nuts on the balljoint
stud nut and the through-bolt. Don’t forget to
refit the washers on both sides of the through-
bolt. If you’re refitting the control arm, be sure
to use thread-locking compound on the
steering arm mounting bolts. Don’t tighten the
through-bolt to the final torque yet. Note:
Thrust arms are marked “L” for the left side,
and “R” for the right side. Be sure to check the
marking before fitting a new arm.
10Support the control arm with a trolley
jack, and raise it to simulate normal ride
height, then tighten the through-bolt to the
torque listed in this Chapter’s Specifications.Refit the wheel and tighten the wheel bolts to
the torque listed in the Chapter 1 Specifi-
cations.
11Have the front end alignment checked at
a dealer service department or qualified
garage.
5 Front strut assembly-
removal and refitting
3
Removal
Note:Although strut assemblies don’t always
fail or wear out simultaneously, renew both left
and right struts at the same time, to prevent
handling peculiarities or abnormal ride quality.
1Loosen but do not remove the front wheel
bolts.
2Raise the front of the vehicle and support it
on axle stands.
3Remove the front wheel.
4Detach all brake hoses and electrical wires
attached to the strut housing.
5Disconnect the electrical connections for
the ABS system, if applicable.
6If you’re removing the left strut, disconnectthe electrical connector for the brake pad
wear sensor.
7Remove the bolt securing the ABS wheel
sensor, if applicable. Remove the brake disc
(see Chapter 9).
8Remove the brake splash shield (see
illustration).
9On 3-Series models, disconnect the anti-
roll bar from its connecting link (see Sec-
tion 2). On 5-Series models, disconnect the
anti-roll bar link from the strut housing (see
Section 2).
10On 3-Series models, disconnect the
control arm balljoint from the steering knuckle
(see Section 3) and the track rod end from the
steering arm (see Section 17).
11On 5-Series models, disconnect the bolts
that attach the steering arm to the strut
housing (see illustration 4.5).
12Pull out the lower end of the strut housing
far enough to clear the end of the control arm
(3-Series) or the steering arm (5-Series).
13Support the weight of the strut and
remove the three mounting nuts at the top of
the strut, located inside the engine
compartment (see illustration)and remove
the strut.
14Remove the strut assembly. If a new
shock absorber (strut cartridge) is being fitted,
see Section 6.
Refitting
15Refitting is the reverse of removal. On
3-Series models, be sure to use new self-
locking nuts on the control arm balljoint, the
track rod end balljoint and the strut upper
mountings. On 5-Series models, make sure
the tang in the steering arm is mated with the
notch in the strut housing (see illustration).
BMW recommends using a thread-locking
compound on the steering arm mounting
bolts. On all models, tighten the fasteners to
the torques listed in this Chapter’s Specifi-
cations.
16When you’re done, drive the vehicle to a
dealer service department or qualified garage
and have the wheel alignment checked, and if
necessary, adjusted.
10•6 Suspension and steering systems
5.15 On 5-Series models, make sure the
tang in the steering arm is mated with the
notch in the strut housing (arrowed)5.13 Support the weight of the strut and
remove the three mounting nuts (arrowed)
at the top of the strut (5-Series shown,
3-Series similar)5.8 To remove the brake splash shield,
remove these three bolts (arrowed)
4.8 Correct orientation of the bush for the
5-Series thrust arm. The arrow on the
rubber bush is aligned with the mark on
the arm, and the centre of the bush is
concentric with the bore4.7c . . . but you may have to use a
hammer to knock the control arm balljoint
stud loose from the steering arm, because
there’s no room to use a puller. A purpose-
made balljoint separator tool would be
better

6 Strut or shock absorber/coil
spring- renewal
4
Note:This section applies to all front strut
assemblies and, on 5-Series models, the rear
coil-over shock absorber assemblies.
1If the struts, shock absorbers or coil springs
exhibit the telltale signs of wear (leaking fluid,
loss of damping capability, chipped, sagging
or cracked coil springs) explore all options
before beginning any work. Strut or shock
absorber assemblies complete with springs
may be available on an exchange basis, which
eliminates much time and work. Whichever
route you choose to take, check on the cost
and availability of parts before dismantling the
vehicle.
Warning: Dismantling a strut or
coil-over shock absorber
assembly is a potentially
dangerous undertaking, and
utmost attention must be directed to the
job, or serious injury may result. Use only a
high-quality spring compressor, and
carefully follow the manufacturer’s
instructions supplied with the tool. After
removing the coil spring from the strut
assembly, set it aside in a safe, isolated
area.
2Remove the strut or shock absorber
assembly (see Section 5 or 11). Mount the
assembly in a vice. Line the vice jaws with
wood or rags to prevent damage to the unit,
and don’t tighten the vice excessively.
3Following the tool manufacturer’s
instructions, fit the spring compressor (these
can be obtained at most car accessory shops,
or it may be possible to hire one) on the
spring, and compress it sufficiently to relieve
all pressure from the suspension support (see
illustration). This can be verified by wiggling
the spring.
4Prise the protective cap off the damper rod
self-locking nut. Loosen the nut (see
illustration)with a spanner while holding thedamper rod stationary with another spanner
or an Allen key.
5Remove the nut, the strut bearing, the
insulator and the large washer. Check the
bearing for smooth operation. If it doesn’t turn
smoothly, renew it. Check the rubber insulator
for cracking and general deterioration. If there
is any separation of the rubber, renew the
insulator.
6Lift off the spring retainer and the rubber
ring at the top of the spring. Check the rubber
ring for cracking and hardness. Renew it if
necessary.
7Carefully lift the compressed spring from
the assembly and set it in a safe place, such
as a steel cabinet.
Warning: Never place your head
near the end of the spring!
8Slide the protective tube and rubber
bumper off the damper rod. If either is
damaged or worn, renew it.
9If you’re working on a front strut, loosen
and remove the threaded collar (see
illustration)and pull the old strut cartridge
from the strut housing. Pour the old oil from
the strut housing.
10On all struts except gas-charged units, fill
the strut housing with 20 to 25 cc (3-Series),
42 to 47 cc (518i and 520i 5-Series models) or
20 to 25 cc (all other 5-Series models) ofengine oil (the oil helps cool the shock
absorber by transferring heat to the strut
housing). Note:It doesn’t matter what
viscosity or grade of engine oil is used.
11Refitting is otherwise the reverse of
removal. Tighten the threaded collar to the
torque listed in this Chapter’s Specifications.
Make sure you align the end of the coil spring
with the shoulder of the rubber ring and with
the spring retainer (see illustration). Tighten
the damper rod nut to the torque listed in this
Chapter’s Specifications.
12Refit the strut or shock absorber
assembly (see Section 5 or 11).
7 Balljoints- check and renewal
3
Check
Note:On 3-Series models, there are two
balljoints on each control arm - one between
the middle of the arm and the subframe, and
the other between the outer end of the arm
and the steering knuckle. On 5-Series models,
there are balljoints on the outer ends of the
control arm and the thrust arm.
1Raise the vehicle and support it securely on
axle stands.
2Visually inspect the rubber boot between
the balljoint and the subframe or steering
knuckle, etc for cuts, tears or leaking grease.
If you note any of these conditions, renew the
control arm or thrust arm - the balljoints are
not available separately.
3Place a large lever under the balljoint, and
try to push the balljoint up. Next, position the
lever between the arm and the subframe or
between the arm and steering knuckle. If you
can see or feel any movement during either
check, a worn balljoint is indicated.
4Have an assistant grasp the tyre at the top
and bottom, and shake the top of the tyre with
an in-and-out motion. Touch the balljoint stud
nut. If any looseness is felt, suspect a worn
balljoint stud or a widened hole in the
subframe or steering knuckle. If the latter
Suspension and steering systems 10•7
6.4 Prise the protective cap off the
damper rod nut, and remove the large nut
(arrowed) - to prevent the damper rod from
turning, place an Allen key in the end of
the shaft6.3 Following the tool manufacturer’s
instructions, fit the spring compressor to
the spring, and compress it sufficiently to
relieve all pressure from the suspension
support
6.11 Make sure you align the end of the
coil spring with the shoulder of the rubber
ring, and with the spring retainer
6.9 Loosen and remove the threaded
collar, and pull the old strut cartridge from
the strut housing - on all struts except
gas-charged units, pour the old oil from
the strut housing. (Spring should have
been removed first!)
10

21 Steering box (5-Series)-
removal and refitting
4
Removal
Note:If you find that the steering box is
defective, it is not recommended that you
overhaul it. Because of the special tools
needed to do the job, it is best to let your
dealer service department overhaul it for you
(otherwise, fit a new unit). Removal and
refitting the steering box is outlined here.
1On 5-Series E28 (“old-shape”) models,
discharge the hydraulic system by depressing
the brake pedal about 20 times.
2Using a large syringe or hand pump, empty
the power steering fluid reservoir (see Chap-
ter 1).
3Raise the front of the vehicle and support it
securely on axle stands.
4Support the front of the engine with a trolley
jack. Place a block of wood between the jack
head and the sump to protect the sump from
damage.
5Remove the pivot bolts from the inner ends
of the front control arms (see Section 4).
6Remove the nuts from the left and right
engine mountings (see Chapter 2).
7Remove the mounting bolts (two on each
side on earlier models, three on each side on
later models) from the subframe crossmember
(see illustration)and remove the subframe.
8Remove the nuts and bolts that secure the
universal joint shaft to the steering box worm
shaft. Slide the universal joint shaft up and off
the worm shaft. Inspect the universal joint
shaft for wear. If it’s stiff or worn, renew it.
9Remove the banjo bolts, and disconnect
the hydraulic pressure line and the return line
from the box (see illustration). Plug the ends
of the lines to prevent fluid loss and
contamination. Discard the sealing washers -
new ones should be used when reassembling.
10Remove the steering box retaining bolts
(see illustrations)and remove the steering
box.
11If it’s necessary to detach the Pitman arm
from the box sector shaft (to have the box
serviced or to switch the arm to a new orrebuilt unit), make a match mark across the
two for correct reassembly. Remove the
Pitman arm retaining nut and washer. Use a
puller to withdraw the arm if necessary.
Refitting
12Refit the Pitman arm by aligning the
match marks made during removal, then
tighten the nut to the torque listed in this
Chapter’s Specifications.
13When fitted the Pitman arm must not have
any measurable endfloat within 100° from the
neutral position. If play exists, have the
following parts checked:
a) Sector shaft and bearings (for wear)
b) Thrust washer and adjuster bolt head (for
wear)
c) Ball nut and worm shaft (for wear)
14Refit the steering box. Align the mark on
the pinion gear shaft with the mark on the
universal joint shaft, and tighten the steering
box bolts to the torque listed in this Chapter’s
Specifications.
15The remainder of refitting is the reverse of
removal. Be sure to use new self-locking nuts
on the universal joint shaft, the centre track
rod, the steering box and the crossmember.
Also, use new sealing washers on the
hydraulic line fittings.
16Refer to Chapter 1 and fill the powersteering reservoir with the recommended
fluid, then bleed the system as described in
Section 23. Check for leakage from the lines
and connections.22 Power steering pump-
removal and refitting
1
Removal
1Raise the vehicle and support it securely on
axle stands. Remove the engine undertray.
2On 5-Series E28 (“old-shape”) models,
discharge the hydraulic system by depressing
the brake pedal about 20 times before
loosening the hydraulic line fittings.
3Disconnect the fluid return hose, and drain
the power steering fluid from the reservoir into
a clean container. Disconnect the pressure
line from the pump.
4If you need to remove the pulley from the
pump, push on the power steering pump
drivebelt by hand to increase the tension, and
unscrew the pulley nuts or bolts.
5Loosen the power steering pump drivebelt
tensioner bolt, and remove the drivebelt (see
Chapter 1).
6Remove the mounting bolts (see
illustrations)and detach the power steering
pump.
Suspension and steering systems 10•15
21.10a This bolt (arrowed) secures the
steering box to the subframe
crossmember. The nut, not visible in this
photo, is accessed through a hole in the
crossmember (engine removed for clarity,
left-hand-drive shown)21.9 Disconnect the power steering
pressure line fitting (right arrow) and the
return line fitting (left arrow). Note that the
return line fitting banjo bolt is larger than
the bolt for the pressure line fitting (left-
hand-drive shown)21.7 Subframe crossmember bolts
(arrowed)
22.6a Typical 3-Series power steering
pump adjusting bolt (arrowed) . . .
21.10b This bolt (arrowed) attaches the
steering box to the body (the nut, not
visible in this photo, is on the front side of
the steering box)
10