2001 BMW 525i Control arms

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[~us~ension, Steering and Brakes - General
This section of the manual covers front and rear suspension,
braking and steering systems, and contains wheel, tire and
wheel alignment information and specifications. Also covered
here are the integrated braking and suspension systems in-
cluding
antilock braking (ABS), traction control (ASCIDSC),
and electronic height control (EHC).
Vehicle ride height information is at the end of this repair
group. Alignment information is in
320 Steering and Wheel
Alignment.
Aluminum suspension components
In order to reduce vehicle weight, aluminum suspension com-
ponents are used in some models. A test with a magnet will
easily reveal the metal used. If working with aluminum com-
ponents, be sure to read and follow the cautions below.
CAUTION-
* Due to the chemical and corrosion characteristics of alumi-
num, do not bring into contact with battery acid.
Do not use wire brushes with brass or iron bristles.
Only use brushes with stainless steel bristles.
Do not expose to flying sparks from
grinding/cutting op-
erations.
Do not subject to steel welding splashes.
Do not expose to temperatures over
80°C (176"F),
even for short periods. Temperatures in painting facili-
ties are not a problem.
The E39 front suspension subframe is used as a rigid mount-
ing platform for the front suspension arms, stabilizer bar and
steering gear.
The suspension arms, known as the lower control arms and
the tension struts (thrust arms), are connected to the
sub-
frame through rubber bushings. The arms are connected to
the steering
knucltles in a double pivot configuration.
Each front strut assembly includes a tubular strut and a coil
spring. The upper strut mount includes a bearing. The lower
end of each strut housing is fitted to the steering knuckle. The
integral wheel bearing and hub are bolted to the steering
Iknucltle.
6-cylinder and V-8 models use different steering systems and
other front suspension components.

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300-5
Suspension, Steering and Brakes - ~enerall
The E39 rear suspension subframe is used as a rigid mount-
ing platform
forthe differential (also called final drive) and rear
suspension components. The differential is mounted to the
subframe and the subframe is bolted to the body through rub-
ber bushings which help isolate drivetrain noise and vibration.
The
€39 rear suspension is known as a modified multi-link
system. Three control arms on each side locate the rear
wheels.
The lowercontrol arm, called the swing arm, is attached to the
wheel bearing carrier through a pivoting integral link.
An eccentric mounting bolt at the rear inner mounting of the
swing arm is used for rear camber adjustment.
The inner end of the upper front control arm, called the trac-
tion strut, is also mounted with an eccentric fastener, used to
adjust rear toe.
Drive axles with constant-velocity (CV) joints at both ends
transfer power
from the differential to the road wheels.
Sedan models
The rear suspension in sedan models uses coil springs over
strut shock absorbers. The bottom of each strut bolts to the
wheel
carrier.The top strut mount attaches just below the rear
parcel shelf of the car.
Sedan models fitted with EDC (Electronic Dampening Con-
trol) use air struts.

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31 0 Front Suspension
General . . . . . . . . . . . . . . . . . . . . . . . . . . . .310-2 Front Suspension Arms . . . . . . . . . . . 310-1 2
Special tools . . . . . . . . . . . . . . . . . . . . . . . . ,310-2 Control arm, removing and installing
Front suspension variations
. . . . . . . . . . . . ,310-4 (6-cylinder models) . . . . . . . . . . . . . . . . . . 31 0-1 2
Control arm, removing and installing Front Strut ' ' ' ' ' ' ' ' ' ' ' ' ' ' '310-4 ("-8 models) , , , , , , , , , , , , , , , , , , , , , , , 310-13 Front strut assembly, removing
Tension strut, removing and installing . . . . 310-16 and installing . . . . . . . . . . . . . . . . . . . . . . . . ,310-5 Tension strut bushing, replacing . . . . . . . . 310-18 Front strut assembly components
(6-cylinder models)
. . . . . . . . . . . . . . . . . . ,310-9 Wheel Bearings, Front . . . . . . . . . . . . . 310-18
iron; strut assembly, disassembling Front Stabilizer Bar . . . . . . . . . . . . . . . 310-22 and assembling . . . . . . . . . . . . . . . . . . . . . ,310-9 Stabilizer bar, removing and installing . . . . 310-22

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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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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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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
. . . . . . . . . . . . . . . . . . . .

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330-1 3
Rear Suspension
1 1 4 Check roll fold of air spring (arrows). Reinstall only if roll fold
is undamaged and formed correctly.
- To install air spring:
Check sealing O-rings at air spring inlet. Replace
if dam-
aged. Do not grease O-rings. Reinstall protective plug.
* Install spring above suspension subframe. Make sure ec-
centric lug at bottom of air spring fits in recess of
subframe
spring seat.
Reattach top spring mounting clips.
- Reattach air line connections.
- Remainder of installation is reverse of removal.
Tightening torques
Air line connection
2 Nm (1 8 in-lb)
Air spring
to wheel bearing carrier 20 Nm (1 5 ft-lb)
Road
wheel to hub 120 510 Nm (89-F-7 ft-lb)
REAR SUSPENSION ARMS,
SUBFRAME AND BUSHINGS
A damaged suspension arm orworn bushings will change the
rear wheel alignment and may adversely affect handling and
stability.
WARNING-
Do not attempt to straighten a damaged suspension arm.
Bending or heating may
weaken the original part. Always re-
olace a damaoed susoension arm.
Rear suspension arm
components
1. Eccentric washer
(for rear toe adjustment)
2. Upper front control arm
(guide link or traction strut)
3. Outer swing arm bushing and
integral link
4. Swing arm (lower control arm)
5. Upper rear control arm
(wishbone)
6. Wheel bearing carrier
7. Circlip
8. Swing arm ball joint
9. Eccentric washer
(rear camber adjustment)

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WARNING
Your common sense, good
judgement, and general alertness are
crucial lo sale and
successlul service
work. Belore attempling any work on
your BMW, be sure to read 001
General Warnings and Cautions
and lhe copyright page
a1 llle Iron1 01
the manual. Review lliese warnings
and cautions each time you prepare
lo work on your
BMW Please also
read any warnings and
caulions lhal
accompany the procedures In !he
manual.
Component locations
see Electrical system
Compression test
113-5
Compressor see
AlC
Condenser see
AlC
Constant velocity (CV) joint
see Maintenance
see also
Driveshall
see also Drive axles
Consumer cutoff
600-10
Control arm see Front suspension
see also Rear suspension,
suspension arms
Coolant (antifreeze) see Maintenance
see also Cooling system
Coolant pump
see Cooling system Cooling system
coolant bleeding
170-14 6-cylinder engine, draininglfilling
170-10
V-8 engine, draininglfilling 170-12
coolant pump 170-3
6-cyiinder engine, replacing 170-1 9
V-8 engine, replacing 170-20 cooling fan 170-4
viscous ciutch fan, removingi
installing 170-14
electric fan, removlngiinstailing 170-1 5
expansion tank, removinglinstalling
170-22
electrically heated (ciiaracterislic
map) therrnostat 170-4
radiator, removinglinstaliing 170-22
service
see Maintenance
therrnostat 170-16
transmission fluid heat exchanger
170-5 troubleshooting 170-7
combuslion leal( test 170-10
pressure test
170-9
Crankshaft oil seals
iront
117-6
rear 11 9-6
Crankshaft speed sensor
see Ignition syslem
Crash sensor
see
Airbag system (SRS), side-impact
airbag crasii sensor
Cruise control clutch switch 612-9
CV joint
see Maintenance
see also Driveshalt
see also Drive axles
CV joint boot
see Maintenance
see also Drive axles
Cylinder head removinglinslaliing
M52 engine 113-8
M52 TU / M54 engine 113-22
M62 engine 113-56
Cylinder head and valvetrain
hydraulic lifters, checking and
replacing
116-7 leak test 116-5 valves 11 6-56
see
alsocylinder head Dashboard
513-7
Deck
lid
seeTrunk lid
Diagnostic monitors
OED-4
Diagnostic trouble codes
(DTCs)
080-7
Digital multimetel
010-17
Differential see Final drive
DLC (data
link connector) 020-4, OED-4
DME (digital motor electronics)
see
130 under appropriate fuel
injection system
see also ignition system
DM-TL (detection module-tank leak)
see
Fuel lank, leak deteclion unit
Drive
belts
see Maintenance
Dome light
seeLighls, interior lights
Door
door
check, replacing 411-4
hinge adjustment 41 1-5
loci(
see Door lock see also Central locking
removinglinslaliing 41
1-2
panel, removinglinstaliing 41 1-7 window
see Door window
Door
check
see Door
Door
handle
see Door lock
Door glass
see Door window
Door
lock
handles and loci(s 515-16
see also Central locking
Door
molding
510-13
Door panel see Door