power BMW 528i 1998 E39 Repair Manual

Downloaded from www.Manualslib.com manuals search engine
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.

Downloaded from www.Manualslib.com manuals search engine
300-1 2
I Sus~ension, Steerincl and Brakes - General
E39 electronic brake and stability control
systems application table
(528i, 54bi) Traction (ASC) I Hydraulic unit in right rear of engine compartment 1
Identifiers
Year (model)
I No precharge pump 1
Manuf. up to 911998 l~utomatic Stability Control plus I Electronic control module next to glove compartment
System
Precharge pump in
lefl front of engine compartment, below
steering fluid reservoir
Separate rotational rate (yaw) and lateral acceleration sensors
I I
Combined rotational rate (yaw) and lateral acceleration sensors
Electronic control
module next to glove compartment
Hydraulic unit in right rear of engine compartment
Manuf. up to 911999
(540i optional)
I I
ABS system
Dynamic Stability Control (Bosch
DSC
Ill v. 5.3)
The electronically controlled
ABS maintains vehicle stability
and control during emergency braking by preventing wheel
lock-up.
ABS provides optimum deceleration and stability dur-
ing adverse conditions. It automatically adjusts brake system
hydraulic pressure at each wheel to prevent wheel lock-up.
Control
moduleihydraulic unit
in right rear of engine compartment
No precharge pump
Manuf. from
911999
(all models)
Automatic Stability Control (ASC)
Dynamic Stability Control (Boscli
DSC Ill v. 5.7)
NOJE-
ASC (Automatic Stability Control) may also be referred to as
ASCiT (Automatic Stability ControkTraction).
ASC works in conjunction with ABS and the engine manage-
ment system to enhance vehicle control. The main function of
the
ASC system is to maintain the contact between the tires
and the road surface under all driving conditions. This is
achieved through exact application and management of brak-
ing and drivetrain forces.
The
ASC system improves traction by electronically applying
the rear brakes when the rear drive wheels are spinning at a
faster rate than the front wheels. The combined
ABSIASC
control module, operating through the ABS hydraulic control
unit, modulates braking force at the rear wheels.
In addition,
ASC overrides the throttle opening to reduce en-
gine torque and maintain vehicle traction. Because the throt-
tle is controlled electronically, the driver cannot increase
engine power output during
ASC intervention regardless of
how far the accelerator pedal is pushed.

Downloaded from www.Manualslib.com manuals search engine
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

Downloaded from www.Manualslib.com manuals search engine
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). - -

Downloaded from www.Manualslib.com manuals search engine
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.

Downloaded from www.Manualslib.com manuals search engine
Steering and Wheel Alignment
Power assist is provided by a belt-driven pump at the lower
left front of the engine. The power steering fluid reservoir is lo-
cated at the left side of the engine compartment.
Power steering pump, removing and
installing
When working with power steering components, absolute
cleanliness is needed to ensure proper operation of the hy-
- Empty power steering fluid reservoir using clean syringe. Do
not reuse fluid.
- Raise front of car. Remove splash shield from under engine.
WARNING-
Make sure the car is firmly supported on jack stands de-
signed for the purpose. Place jack stands beneath structural
chassis points. Do not place jack stands under suspension
Darts.
Remove drive belt from power steering pump. See
020 Main-
tenance.
Remove alternator cooling duct
Remove fluid hoses from pump. Plug openings in pump and
hose ends.
Remove pump front mounting bolts
(A).
Remove fluid line support bracket (B)
Remove pump rear mounting bolt (arrow)
- Installation is reverse of removal, noting the following:
Make sure all thread bores, bolts, nuts, fluid couplings and
mating
surfaces are clean, and inside surface of multi-
ribbed-belt is free of grease and dirt.
Use new sealing washers when reattaching power steer-
ing pressure lines.
Make sure hoses have adequate clearance from chassis.
Install front pump fasteners.

Downloaded from www.Manualslib.com manuals search engine
-
-steering and wheel -. Alignment I
< Hand tighten rear suppoll nut (arrow) against mounting
bracket.
Install rear mounting nut and tighten.
Do not over-torque banjo bolts.
* Fill and bleed power steering system as described later.
Tightening torques
Hydraulic lines to steering pump (banjo bolts)
a MlO 12 Nm (9 ft-lb)
. M14 35 Nm (26 ft-lb)
MI6 40 Nm (30 ft-lb)
. MI8 45 Nm (33 ft-lb)
Pump
brackets to engine block 25 Nm (18 ft-lb)
Rear pump support stud to pump housing
22 Nm (16 ft-lb)
Power steering system, bleeding and filling
- With engine off, fill power steering fluid reservoir with clean
fluid. Fill level to MAX
mark on dip stick.
- Start engine. Turn steering wheel twice to left lock and right I
lock.
- Recheck fluid level with engine off. Fill to MAX.

Downloaded from www.Manualslib.com manuals search engine
i Steering and Wheel Alignment
RACK AND PINION STEERING
(6-CYLINDER MODELS)
Refer to the steering components illustration when perform-
ing the procedures below.
Rack and pinion steering
components
(6-cylinder models)
1. Power steering fluid reservoir
2. Fluid supply line
3. Power steering pump
4. Copper sealing ring
5. Banjo bolt MI4
6. Banjo bolt MI6
7. Power steering rack
8. Fluid return line
9. Pressurized fluid line
10. Steering fluid cooler
11. Rack boot components
12. Tie rod nut
13. Washer
14. Outer tie rod end
15. Tie rod locking ring
16. Outer tie rod end loclc nut
17. Inner tie rod
18. Hydraulic control valve
Steering rack, removing and installing
- Remove steering wheel as described earlier.
- Raise front of car, and remove front wheels.
WARNING -
Male sure the car is firmly supported on jack stands de-
signed for the purpose. Place jack stands beneath structural
chassis points. Do
not place jack stands under suspension
parts.
- Remove splash shield from under engine.
- Remove right and lefl engine mount fasteners
-" ., - , . ,

Downloaded from www.Manualslib.com manuals search engine
/steering and Wheel Alignment
Raise engine approximately 40 mm (1.6 in). See 110 Engine
Removal and installation.
Remove right and left engine mounts and remove mount
brackets from subframe.
Empty power steering fluid reservoir using a clean syringe.
Do not reuse power steering fluid.
Remove right tie rod fastener (arrow) from right steering
Itnuckle. Repeat for left.
4 Press right tie rod out of right steering knucltle using BMW
special tool 31
2 240. Repeat for left.
/ ~ock nut Loclting ring
0012143
4 Malte reference measurement (A) of right tie rod end to tie
rod. Record measurement. Repeat for left.
NOJE-
0 Accurate measurement of tie rod end with reference to tie
rod will help approximate correct wheel alignment during
reassembly.
Note correct placement of inner taper on
locling ring
Remove fluid line
banjo bolts (arrows)
from steering rack.

Downloaded from www.Manualslib.com manuals search engine
Steering and Wheel ~lignmentl
Remove lower steering column flexible joint pinch bolt (ar-
row). Pull flexible joint off steering rack shaft.
Remove steering rack mounting bolts. Remove steering
raclc
from subframe by pulling it to left.
Installation is reverse of removal, noting the following:
Make sure all thread bores, bolts, nuts, splines and mating
surfaces are clean.
Use new steering rack mounting bolts. Tighten in two stag-
es. Note tightening instructions in torque table below.
Use anti-seize paste on inner tie rod threads.
Use new self-loclting nuts wherever applicable.
Use keved
comDonents to reassemble steerino column
flexible\oint to ;teering raclt shaft. u
Use new bolt at steering shaft coupling.
Use new sealing O-rings on banjo fittings.
Do not over-torque banjo bolts.
Fill and bleed power steering system as described earlier.
Use tie rod measurement previously made (measurement
A) to temporarily set toe.
Have car professionally aligned.
Tightening torques Hydraulic lines to steering rack (use new O-ring
seals)
M14 banjo bolt 35 Nrn (26 ft-lb)
. M16 banjo bolt 40 Nm (30 ft-lb)
Steering shaft coupling
to rack (use new bolt) 19 Nm (14 it-lb)
Steering rack to subframe (use new bolts)
- initial torque 50 Nm (37 ft-lb)
Torque angle 90"
Tie rod
to Steering knuckle (replace self-locking
65 Nm (48 ft-lb)
nut)
- to Steering rack 71 Nm (52 ft-ib)
Outer tie rod end lock nut
51 Nm (38 ft-lb)