1999 BMW 540i Ride height

Downloaded from www.Manualslib.com manuals search engine
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

Downloaded from www.Manualslib.com manuals search engine
[~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.

Downloaded from www.Manualslib.com manuals search engine
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.

Downloaded from www.Manualslib.com manuals search engine
300-1 4
I Susoension. Steerina and Brakes - General
DSC system I
Dynamic Stability Control (DSC)
Dynamic Stability Control (DSC) utilizes many principles and
components of the ASC traction control system. DSC is ac-
tive throughoutthe driving range, unlike ASC which is only ac-
tive during acceleration and braking. DSC helps stabilize the
vehicle in cornering and avoidance maneuvers by adjusting
engine controls such as throttle, ignition, fuel injection and the
application of
brake pressure individually to the wheels.
Inputs
fi- 0
2 4-* .. o
[11-' IJ
411m4
3?-
G
4 The DSC control module uses various inputs to determine
vehicle instability during braking, cornering, or reduced trac-
tion situations. Based upon these inputs the ABSIDSC con-
trol module sends outputs to the engine control module and
the ABSIDSC hydraulic unit to activate torque reduction pro-
tocols and braking intervention.
-
ABSIDSC control module
OUI~YIS
4
The DSC system can be toggled on and off by a switch
mounted on the center console. Turning off the DSC system
does not disable ABS or ASC functions.
+
Measure ride height (A) from center of fender arch to bottom
of wheel rim.
Car in normal loaded position on the ground. See Normal
loaded position.
Engine
control
module
Specified tires and wheels, correct tire pressure, even tire
wear
-'* 9-
.%A
Correct wheel bearing play
T'== ..t, 9 B
-.m
Model with air suspension (EHC): Disconnect electrical har-
ness connector to air supply pump to prevent automatic
height regulation.
When finished, reset ride height using BMW diagnostic
scan tools DIS or
MoDiC.
NOTE-
Airsupply pump is located beneath a cover under the spare
tire in the floor of the cargo compartment.
- If ride height is outside specification listed, install new
springs. Suspension spring removal and installation is cov-
ered in
310 Front Suspension and 330 Rear Suspension.
Normal loaded position
Each front seat 68 kg (150 Ib)
Center of rear seat 68 kg (150 lb)
Trunk 21 kg (46 lb)
Fuel tank full

Downloaded from www.Manualslib.com manuals search engine
Suspension, Steering and Brakes - General
Front ride height specifications
(measurement
A)
E39 6-cylinder (5251,5281,530i) models
E39
V8 (540i) models
Wheel size
15 inch
16 inch
17 inch
18 inch
Maximum variation between sides: 10 mm (0.4 in)
Maximum deviation from specifications: 10 mm (0.4 in)
Standard
suspension
579 mm (22.8 in)
592 mm (23.3 in)
607 mm (23.9 in)
620 mm (24.4 in)
Wheel size
15 inch
16 inch
17 inch
18 inch Sports suspension
559
mm (22.0 in)
572 mm (22.5 in)
587 mm (23.1 in)
600 mm (23.6 in)
Maximum variation between sides: 10 mm (0.4 in)
Maximum deviation from specifications: 10 mm (0.4 in)
Standard
suspension
579 mm (22.8 in)
592
mm (23.3 in)
607 mm (23.9 in)
620 mm (24.4 in) Rough
road suspension
599
mm (23.6 in)
612 mm (24.1 in)
627 mm (24.7 in)
640 mm (25.2 in)
Sports suspension
559 mm (22.0 in)
572 mm (22.5 in)
587 mm (23.1 in)
600
mm (23.6 in)
M sports package
559 mm (22.0 in)
572 mm (22.5 in)
587 mm (23.1 in)
600 mm (23.6 in)
Rough road suspension 599 mm (23.6 in)
612
mm (24.1 in)
627
mm (24.7 in)
640
mm (25.2 in)
M sports package
562 mm (22.1 in)
575 mm (22.6 in)
590
mm (23.2 in)
603
mm (23.7 in)

Downloaded from www.Manualslib.com manuals search engine
300-1 6
I Suspension, Steering and Brakes - General
Rear
ride height specifications
(measurement
A)
E39 6-cylinder (5251,5281,530i) models
E39 VB (540i) models
Wheel size
15 inch
16 inch
17 inch
18 inch
Maximum variation between sides: 10
mm (.04 in)
Maximum deviation from specifications: 10
mm (.04 in)
Standard
suspension
547 mm (21.5 in)
560
mm (22.0 in)
575 mm (22.6 in)
588 mm (23.1 in)
I I I I I
Maximum variation between sides: 10 mm (.04 in)
Wheel
size
15 inch
16 inch
575 mm (22.6 in)
Maximum deviation from specifications: 10 mm
(.04 in)
Sports suspension
532 mm (20.9 in)
545 mm (21.5 in)
560 mm (22.0 in)
573
mm (22.6 in)
Rough road
suspension
567
mm (22.3 in)
580 mm
( in)
E39 Sport Wagon models
M sports package
536
mm (21.1 in)
549 mm (21.6 in)
Standard
suspension
547 mm (21.5 in)
560 mm (22.0 in)
588 mm (23.1
in)l 573 mm (22.6 in)/ 603 mm (23.7 in)l 608 mm (23.9 in)l 577 mm (22.7 in)
560
mm (22.0
in) Ride level
control
562
mm (22.1 in)
575 mm (22.6 in)
590 mm (23.2 in)
603 mm (23.7 in)
Sports suspension 532
mm (20.9 in)
545 mm (21.5 in)
590
mm (23.2 in) Rough
road
suspension
567
mm (22.3 in)
580 mm (22.8 in)
595 mm (23.4 in)
608 mm (23.9 in)
Ride level control
562
mm (22.1 in)
575 mm (22.6 in)
Wheel size
15 inch
M sports package
532
mm (20.9 in)
545
mm (21.5 in)
560 mm (22.0 in)
573 mm (22.6 in)
595
mm (23.4 in)
Sports suspension with
air spring
548 mm (21.5 in)
Standard
suspension
548
mm (21.5 in)
16 inch
17 inch
18 inch 564
mm (22.2
in)
Maximum variation between sides: 10 mm
(.04 in)
Maximum deviation from specifications: 10 mm
(.04 in) 561
mm (22.0 in)
576
mm (22.6 in)
589
mrn (23.1 in)
561
mm (22.0 in)
576 mm (22.6 in)
589 mm (23.1 in) Ride level
control
563
mm (22.1 in) Rough road suspension
568 mm (22.4 in)
576 mm (21.6 in)
591 mm (23.2 in)
604 mm (23.7 in) 581
mm (22.9
in)
596
mm (23.5 in)
609 mm (24.0 in)

Downloaded from www.Manualslib.com manuals search engine
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)

Downloaded from www.Manualslib.com manuals search engine
Front Suspension
< Use BMW special tool 31 2 240 or equivalent to separate
control arm ball joint from steering ltnuckle.
- When installing control arm, make sure all thread bores.
bolts, nuts and mating surfaces are clean.
- Install bushing end of control arm to subframe, using wash-
ers on both sides of bolt and a new self-locking nut. Do not
tighten nut at this time.
- Install control arm ball joint to steering lknucltle using a new
self-locking nut. Tighten fully.
- Install wheel and lower car.
- Load car to normal loaded position as described under Ride
height. See
300 Suspension, Steering and Brakes-Gen-
eral. Bounce suspension a few times.
- With car on ground and loaded, tighten control arm bushing
through-bolt.
Tightening torques
Control arm to steering ltnuckle
80 Nm (59 ft-lb)
Control arm to subframe 110 Nm (81 It-lb)
Road wheel to hub 120ilO Nm (8957 it-lb)
Control arm, removing and installing
(V-8 models)
- Raise car and remove wheel
WARNING-
Make sure that the car is firmly supported on jack stands de-
signed for the purpose. Place jack stands underneath struc-
tural
cliassis points. Do not place jack stands under
suspension parts.
Loosen and remove stabilizer bar link mounting nut
(A) while
counterholding ball joint
(B). Disconnect stabilizer link from
stabilizer bar.
- Cars equipped with vertical headlight adjustment system:
Disconnect control arm from level sensor.