Steering rack BMW 528i 1997 E39 User Guide
Page 621 of 1002
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300 Suspension. Steering and Brakes .
Genera8
General ........................... .30 0.2
Aluminum suspension components
...... .30 0.2
Front Suspension ................. .30 0.2
Front suspension 6-cylinder models
(525i.5281. 530i) ..................... .30 0.3
Front suspension V-8 models (540i) ...... .30 0.4
Rear Suspension .................. .30 0.5
Sedan models
....................... .30 0.5
Rear suspension sedan models ........ .30 0.6
Sport Wagon models ................. .30 0.6
Rear suspension Sport Wagon
(with coil springs)
.................... .30 0.7
Rear suspension Sport Wagon
(EHC with air springs)
................. .30 0.8
EHC operational diagram .............. .30 0.9
Steering ......................... .30 0.10
Rack-and-pinion steering ............. .30 0.10
Recirculating ball and nut steering ...... .30 0.10
..................... Brake System 300-10
Wheels and Tires ................. 300-1 1
............... Rim and tire sizes table 300-1 1
Electronic Brake and Stability
.................. Control Systems 300-1 1
E39 electronic brake and stability
........ control systems application table 300-12
........................ ABS system 300-1 2
Automatic Stability Control (ASC)
....... 300-12
ABSIASC traction control system ....... 300-13
Dynamic Stability Control (DSC)
........ 300-14
Ride Height ....................... 300-14
......... Front ride height specifications 300-1 5
......... Rear ride height specifications 300-16
Page 626 of 1002
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300-6
/Suspension, Steering and Brakes - General
Rear suspension sedan models
Coil spring
Strut
-
'01 arm
Sport Wagon models
In order to provide a wide, ilat iloor in the cargo compartment,
the rear suspension on the Sport Wagon is unique to itself.
The shoclcabsorber is attached diagonally between the lower
swing arm and a mounting bracket on the subframe. The
spring on each side is mounted between a perch at the top
oi
the wheel bearing carrier and the bottom of the cargo com-
partment floor.
Starting with
1999 Sporl Wagon models, a self-leveling air
suspension system with electronic height control (EHC) was introduced. The system is standard on
V-8 models and op-
tional on 6-cylinder models.
On models fitted with electronic height control (EHC) rear
suspension, the standard coil springs are replaced by air
springs. Air pressure in the air springs is automatically con-
trolled by the
EHC system to compensate for ride height and
load variations.
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300-1 0
/Suspension, Steering and Brakes - General
The steering system features variable power assist provided
by an engine-driven hydraulic pump.
Rack and pinion steering
6-cylinder models
(525i, 5281, 5300
Two types of steering systems are used in E39 models. 6-
cylinder (525i, 5281, 530i) models are equipped with a steer-
ing rack system. V-8
(540i) models are equipped with a re-
circulating ball and nut steering gearbox.
Rack-and-pinion steering
Steering components in 6-cylinder models consist of a rack-
and-pinion type steering gear and connecting linltage to the
road wheels.
The steering linkage connects the rack-and-pinion unit
through tie rods to the steering knucltles. The tie rod ends al-
low the wheels to pivot and react to suspension travel.
Recirculating ball and nut steering
V-8 models
(540i)
I
Recirculating ball and nut steering
Recirculating ball and nut steering in V-8 models consists of a
steering box with integrated hydraulic control valve and con-
necting linkage to the road wheels.
Thesteering linkageconnects the steering gearbox through a
pitman arm to the wheels. An idler arm maintains correct toe
angle. The tie rod allow the wheels to pivot and react to sus-
pension travel.
E39 cars are equipped with power disc brakes with integral
antilock brakes (ABS). The parking bralte is a dual-drum sys-
tem integrated with the rear brake rotors.
Power assist is provided by a vacuum booster when the en-
gine is running. The brake pedal
pushrod is connected direct-
ly to the master cylinder, so failure of the vacuum booster
does not normally result in total
bralte failure.
Each disc bralte uses a caliper with a single hydraulic cylin-
der. Brake pads in the left front and right rear contain wear
sensors. When brake pads need replacement, the sensors il-
luminate a light on the dashboard.
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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)
Page 640 of 1002
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31 0-4
I Front Suspension
6-cylinder models
12 3 4 5
V-8 models
16 7 4
Front suspension
variations
1. Steering knuckle
2. Tension strut (thrust arm)
3. Steering rack
4. Front suspension
subframe
5. Outer tie rod
6. Control arm
7. Steering box
8. Idler arm
9. Center tie rod
The front suspension
shoclc absorbers on E39 cars are
MacPherson struts. The strut is a major component of the
front suspension and supports the spring. Most strut assem-
bly components are available as replacement parts. Always
replace struts and springs in pairs.
Front strut, upper strut mount or spring replacement is a two-
step procedure:
Removal of strut assembly from vehicle
Disassembly and replacement of component on
work
bench
Page 659 of 1002
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1 320 Steering and Wheel Alignment
General ........................... .32 0.2
Special tools
........................ .32 0.2
Steering system
..................... .32 0.4
Steering system variations
............. .32 0.5
Steering system warnings and cautions
... .32 0.6
Steering Wheel .................... .32 0.7
Steering wheel. removal and installation
.. .32 0.7
Steering Column ................. .32 0.1 0
Steering column components .......... .32 0.10
Steering column trim, removing
and replacing
...................... .32 0.10
lgnition switch ring antenna (EWS).
removing and installing
............... .32 0.1 1
lgnition lock cylinder.
removing and installing
............... .32 0-1 1
Steering column lock. removing
and installing
....................... .32 0.12
lgnition
interloclc cable. removing and installing
(models with automatic transmission)
... .32 0.13
Interlock cable. adjusting
(models with automatic transmission)
... .32 0.14
Steering column. removing and installing
. .32 0.14
Steering column adjustment motors.
removing and installing
............... .32 0.16
Power Steering Pump ............. .32 0.17
Power steering pump. removing
and installing
....................... .32 0.1 7
Power steering system.
bleeding and filling
.................. .32 0.18
Rack and Pinion Steering
(6-cylinder models)
............... 320-19
Rack and pinion steering components
(6-cylinder models)
.................. 320-1 9
Steering rack. removing and installing
.... 320-19
Steering
rack boot. replacing ........... 320-22
Tie rod (outer). replacing
.............. 320-22
Tie rod (inner). replacing
.............. 320-23
Steering Gearbox (V-8 models) .... 320-24
Steering gearbox system components
. .
(V-8 models) ....................... 320-24
Steering gearbox, removing and installing 320-25
Pitman arm. removing and installing ..... 320-28
Pitman arm. adjusting ................ 320-29
Steering idler arm. removing
and installing
....................... 320-30
Idler arm bushing. replacing ........... 320-31
Center tie rod. replacing
.............. 320-32
Wheel Alignment .................. 320-33
Camber
........................... 320-33
Caster
............................ 320-33
Front toe and toe difference angle
....... 320-34
Reartoe ........................... 320-34
Preparing for alignment
............... 320-35
Alignment specifications tables
......... 320-35
Page 662 of 1002
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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). - -
Page 663 of 1002
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Steering and Wheel Alignment
I Rack and r in ion steering 1 Steering system variations
I 6-~~linder'rnodels (525i,>28i, 530i) / 1. Left tie rod
2. Right tie rod
3. Steering rack
4. Steering gearbox
5. idler arm
6. Center tie rod
7. Steering knuckle
Recirculating ball and nut steering
r V-8 models 154Oib
Page 671 of 1002
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Steering and Wheel Alignment
4 Release lock (A) and pull up on harness connector (6) to dis-
connect ignition switch harness.
. Remove wire harness bracket fastener (C).
4 Remove shear bolts (arrows) using a chisel or punch.
NOTE-
The shear bolts can be drilled and then removed using an
easy-out.
- Remove steering column lock housing.
- Installation is reverse of removal.
Tighten new shear bolts until bolt heads shear off.
ignition interlock cable, removing and
installing (models
with automatic
transmission)
- Remove steering column trim panels as described earlier.
4 Loosen and disconnect interlock cable (arrow) from ignition
lock assembly.
- Remove center console trim panel.
Page 674 of 1002
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I Steering and Wheel Alignment
- Installation is reverse of removal, noting the following:
Replace shear bolts at steering column mounting bracket.
Tighten until bolt heads shear off.
Make sure
interlock cable snaps into place.
When installing column top trim panel, replace expansion
nut for trim retaining screw.
NOTE-
The steering angle sensor must be coded using a BMW scan
tool if it has been replaced.
A steering angle offset check
must then be carried out using the same
BMW scan tool.
CAUTION-
Check steering system for freedom of movement through en-
tire steering column
adiustment range.
Tightening torques Steering shaft coupler
to steering shaft 25 Nm (18 ft-lb)
(replace bolt)
Steering column to body
22 Nm (16 ft-lb)
Steering column adjustment motors,
removing and installing
Remove lower dash panel mounting fasteners (A) and (B).
- Lower panel and disconnect wiring harness from back side.
- Remove steering column lower trim panel. See Steering col-
umn trim, removing and replacing.
- Disconnect electrical harness from motor.
Remove motor mounting fasteners (arrows)
Slide motor to side and forward to remove.
Installation is reverse of removal.