Page 630 of 1002

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.
Page 640 of 1002
Downloaded from www.Manualslib.com manuals search engine
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

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
Page 663 of 1002
Downloaded from www.Manualslib.com manuals search engine
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 688 of 1002

Downloaded from www.Manualslib.com manuals search engine
I Steering and Wheel Alignment
I I 4 Gap A = 0.5 - 8.5 mm (0.02 - 0.33 in)
- Reinstall inner control arm bolts
Tightening torques
Control arm to
subframe 78 Nm (58 it-lb)
(tighten with wheel on ground)
Pitman arm pinch bolt (note direction of threads) 61 Nm (45 ft-lb)
Steering idler arm, removing and installing
The idler arm is bolted to the subframe through a bushing.
The bushing is subject to wear and is available as a replace-
ment part.
- Raise front of car. Remove splash shield from under engine.
WARNING -
Male sure the car is firmly supported on jaclc stands de-
signed for the purpose. Place jack stands beneath structural
chassis points. Do not place jack stands under suspension
parts.
4 Remove center tie rod fastener and press tie rod out of idler
arm with
BMW special tool 32 1 190.
- Remove idler arm mounting bolt through opening in sub-
frame and remove idler arm from car.
- Installation is reverse of removal.
Make sure all thread bores, bolts, nuts and mating surfac-
es are clean.
Use new self
loclting nuts to mount idler arm to subframe
and center tie rod to idler arm.
If idler arm or idler arm bushing is replaced, adjust
pitman
arm as described earlier.
Have car professionally aligned.
Tightening torques
Center tie rod to idler arm 65 Nm (48 ft-ib)
(replace self-locking nut)
Idler arm to front subirame
(replace self-locking nut) 62
Nm (46 it-lb)
Page 689 of 1002
Downloaded from www.Manualslib.com manuals search engine
320-31
Steering and Wheel ~li~nrnentl
ldler arm bushing, replacing
- Remove idler arm as described earlier.
< Press out bushing. Use BMW special tools 32 1 050 and 32
2 032 or equivalent press fittings.
4 Press in new bushing with BMW special tools 33 1 305 and
32 2 032 or equivalent press fittings.
4 Press new bushing in correct direction (arrow).
u ..... "A",
Press bushing in until lip makes firm contact (A) with idler
arm.
I
Installation is the reverse of removal
Use new self locking nuts to mount idler arm to
subframe
and traclc arm.
a Adjust pitman arm height as described earlier.
Have vehicle professionally aligned.
Tightening torques Center tie rod to idler arm
65 Nm (48 ft-lb)
;nl?mmn / (replace self-locking nut)
ldler arm to front
subframe
(replace sell-locking nut) 62
Nm (46 ft-lb)
Page 690 of 1002

Downloaded from www.Manualslib.com manuals search engine
320-32
Steering and Wheel Alignment
Center tie
rod, replacing
- Raise front of car. Remove splash shield from under engine.
WARNING-
Make sure tlie car is firmly supported on jack stands de-
signed for the purpose. Place jack stands beneath structural
cliassis points. Do not place jack stands under suspension
parts.
- Measure length of left and right (outer) tie rods. Write down
measurements.
NOTE-
Accurate measurement of the tie rod end with reference to
the center tie rod will help approximate correct wheel align-
ment when new parts are installed.
4 Remove self-loclting nuts connecting center tie rod to pitman
and idler arms. Press tie rod off pitman and idler arms using
BMW special tool
32 1 190 or equivalent.
4 Loosen left tie rod clamping bolt (arrow). Unscrew left tie rod
from center tie rod. Repeat for right.
- Installation is reverse of removal.
Malte sure all threaded parts are clean.
. Coat threads with antiseize compound.
Replace self-loclting nuts.
Check tie rod end ball joints and idler arm bushing for wear.
Use tie rod measurements previously made to temporarily
set toe.
- Have car professionally aligned.
Tightening torques
Center tie rod to
pitman and idler arms 65 Nm (48 ft-lb)
(replace self-locking nuts)
Left or right outer
tie rod clamping bolt 27 Nm (20 it-lb)
Page 968 of 1002

Downloaded from www.Manualslib.com manuals search engine
OBD-8
I On-Board Diagnostics
DTC digit interpretation
1st digit
P powertrain
B body
C chassis
2nd digit
0 SAE
1 BMW
3rd digit
0
1
2
3
4
5
6
7
4th - 5th digits total
system
airlfuei induction
fuel injection
ignition system or misfire
auxiliary emission control
vehicle speed
& idle control
ECM
inputs/outputs
transmission
individual circuits or
components
DTC example: P 0 3 0 6
P: A powertrain problem
0: SAE sanctioned or 'generic'
a 3: Related to an ignition system / misfire
06 Misfire detected at cylinder #6
DTCs provide a freeze frame or snap-shot of a vehicle
performance or emissions fault at the moment that the fault
first occurs. This information is accessible through generic
OED I1 scan tools.
Freeze frame data contains, but is not limited to, the following
information:
Engine load (calculated)
Engine rpm
Short and
long term fuel trim
Vehicle speed
Coolant temperature Intake manifold pressure
Open/closed loop operation
Fuel pressure (if available)
DTC