2006 BMW X5 rear suspension

TABLE OF CONTENTS
Subject Page
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Body . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Hood/Front Grille . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Doors/Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Interior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Climate Control Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Cargo Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Tailgate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Drivetrain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
Front Suspension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Rear Suspension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
EHC Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Steering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
Wheels & Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
Fuel Supply System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
Exhaust System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
Power Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
Component Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
STO36 X5

2
Introduction
The X5 marks BMW’s introduction into the luxury “Sports Activity Vehicle (SAV)” niche seg-
ment of the Sport Utility Vehicle market. While carrying the designation X5, the vehicle is not
based on the 5 Series but it is its own new car-like platform. The X5 is offered with two
engine variants:
• The 4.4 liter M62 TU engine equipped with the A5S 440 Z automatic transmission.
• The 3 liter M54 engine with either the GM 5 automatic or 5 speed manual transmission
The X5 incorporates the following
features:
• Four wheel independent sus-
pension (BMW tradition)
• Full time - all wheel drive
(planetary gear transfer case)
• All road vehicle (ON/OFF road
capabilities)
• High ground clearance
• Unitized body and Chassis
(car like ride and handling)
• Double pivot front suspension
• “Integral Link” rear suspen-
sion with air spring self level-
ing
• X5 specific traction control
system
Two different suspension options are offered (standard and sport) with different springs,
shock absorbers and stabilizers.
The X5 has 180 mm ground clearance, for both suspensions to allow off road travel.
However, the suspension travel is the same as the E39 which allows the X5 to retain a car
like feel when driven every day.
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3
Body
The design of the X5 originated in California at BMW’s Design Works. The SAV look was
further developed and refined in Munich. Traditional BMW features such as the Kidney
grilles, quad headlights, reverse link rear side window trim and typical rear tail light treat-
ment allow the X5 to assume a BMW identity. Yet the unique side and hood treatments as
well as the large wheel house openings and high ground clearance set the X5 apart as its
own distinctive vehicle.
The design criteria for the X5 was to develop a vehicle with the superb handling and sporty
driving characteristics that are typically BMW, yet produce an all wheel drive vehicle that can
also be used off-road. This was achieved through the use of independent front suspension
and multi-link rear suspension components that are taken from the E38/E39 vehicle design
and expanded by the addition of front drive components.
The entire body shell/frame assembly of the
X5 is reinforced to ensure optimized body
rigidity.
In addition to the cross bracing on the front
suspension/engine carrier, an additional
panel is installed between the bulkhead and
transmission tunnel.
The floor pan of the X5 is reinforced with
additional ribbing and cross braces to
increase the lateral rigidity. A continuous seat
cross brace is connected to the floor pan
and side sill for reinforcement.
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Cross
Brace
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Reinforcement Panel

33
Rear Suspension
The rear suspension is the “intragal” multi-link design taken from the E38/E39 vehicles.
Several components AER made from aluminum to erduce the unsprung weight. The X5
with the M62TU engine uses the EHC (air spring) suspension system. The EHC functions
the same as the E39 Sport Wagon with only minor differences to the components and lay-
out of the system. The X5 with the M54 engine will use standard springs in the rear with the
EHC system as an option. The rear struts on the X5 are mounted to the body instead of
the sub-frame.
The rear axle sub-frame is mounted to the body through four bushings (larger than E38) for
increased load and comfort. The rear differential is mounted through three rubber bushings
two in the front and one hydromount in the rear. The wheel bearings are similar to the E39
but incorporate different seals - designed for off-road use.
New special tools are available for adjusting the rear suspension due to the limited space.
Rear Axle Technical Data
Track: 1576mm
Toe In: 18 Feet
Camber 1 Degree 50 Feet

34
Rear Suspension Alignment
As with other BMW multi-link suspensions, the X5 rear suspension is adjustable for Camber
and Toe-in. Due to the limited space, special tools have been produced for aligning the rear
suspension.
The Camber is adjusted through the eccentric bushings at the upper control link arm.
The toe-in is adjusted at the lower control arm mount.
Camber Eccentric
Toe-In Eccentric
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35
Overview of EHC Control System
The control philosophy of EHC is to "Initiate a control sequence only when necessary". The
system offers the following advantages:
• The control system operates independently from the vehicle’s engine (no engine driven
hydraulic pump system as per previous self leveling systems).
• Individual control of the rear wheels is possible
• An uneven load is identified and compensated for
• Uneven road surfaces are identified and not compensated for
• Automatic control is interrupted when cornering
• The system is diagnosable using the DIS or MoDiC
The air suspension system consists of the following components:
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Air Springs
The air spring is made from a flexible rubber material. It
forms an air tight cavity which provides the calculated spring
rate required for the sport wagon.
As the spring compresses downward the bottom edge of
the rubber material rolls along the vertical surface of the
base mount cylinder.
Air is added or removed from the air spring through its top
port. The top port of each spring is connected to a reser-
voir and the air supply pipes. The reservoirs are required to
hold additional air due to the compact design of the springs.
Rear Axle Level Sensors
Hall effect sensors are mounted on the left
and right sides of the rear suspension for ride
height detection. They are pivoted by a cou-
pling rod through the rear axle swing arms.
The hall sensors produce a varying voltage
input to the control module as the suspension
height changes.
If the vehicle is equipped with Xenon head-
lights the right side sensor contains an addi-
tional sensor for the automatic headlight level
adjustment system.
Warning Display
If the system is faulted and off-line or set in the transport mode, the following is displayed:
High Cluster: A message is posted in the high cluster matrix display.
E39 Features 07
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48
Wheels and Tires
Light alloy wheels are standard equipment on the X5.
The wheels sizes include:
3 Liter version
• Standard Wheel - 7.5J x17 SEH2
• Standard Tires - 235/65R - 17 H rated all season
Front and Rear
4.4 Liter version standard suspension
• Standard Wheel - 8.5J x 18 EH2
• Standard Tires - 255/55R - 18 H rated all season
Front and Rear
4.4 Liter version sports suspension
• Standard Wheels - 9J x 19 EH2 FRONT
10J x 19 EH2 REAR
• Standard Tires - 255/50R -19 Front/285/45R - 19
Rear V rated
The X5 uses a two piece lug bolt that incorporates a spacer wash-
er and features anti-corrosion coating. The tightening torque on the
lug bolts is 130Nm +/- 10Nm. Advantages of using the spacer
washer include:
• Longer expansion length for the bolt.
• A better fit to the wheel
• The spacer washer is fixed to the wheel when tightening and
the lug bolt turns relative to it.