1999 BMW 528i Suspension

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Rear Suspension
ELECTRONIC HEIGHT CONTROL
(EHC) COMPONENT REPLACEMENT
Sport Premium rear suspension is an option on Sport Wagon
models and standard on
1999 and later V-8 Sport Wagons.
This suspension incorporates electronic height control
(EHC)
using air springs.
With vehicle lifted off the ground,
if the rear air springs can be
compressed by hand, either the spring is defective or the sys-
tem is depressurized.
Locate
EHC faults using BMW scan tools DIS or MoDiC. EHC
description and some troubleshooting is covered in 300 Sus-
pension, Steering and Brakes-General.
Air spring replacement is covered earlier in this chapter. See
Air spring, removing and installing.
CAUTION-
Maintain high levels of cleanliness around air line connec-
tions when disassembling and assembling air suspension
components. Even
small dirt particles can cause leakage in
the pressurized system.
Electronic height control
(EHC) components
1. Air spring
2. 1 liter air reservoir
3. EHC control module
4. Air supply distributor
5. Airsupply pump
(under spare tire)
6. Air spring mounting bolt
(at wheel bearing carrier)
7. Rear ride height sensors
(Hall effect)
8. Air supply pump relay

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-- I
I: ... . -. Rear Suspension! -- .- -
Air compressor pump relay, removing and
installing
- Working in cargo compartment, remove spare wheel.
4 Remove air supply pump fasteners (arrows). Turn pump
over.
- Turn relay plug 45" and remove relay.
EHC control module, removing and
installing
The EHC control module is mounted on the right side of the
spare tire
well in the cargo compartment.
- Remove spare tire.
4 Remove electrical components cover (A).
- Release control module wiring harness plug loclting clip (B)
and remove module.
- Installation is reverse of removal.
- After assembly, reset ride height using BMW diagnostic scan
tool DIS.
Air supply unit, removing and installing
CAUTION-
Maintain high levels of cleanliness around air line connec-
tions when disassembling and assembling air suspension
components. Even small dirt particles can cause
leakage in
the pressurized system.
When the airsupply unit is removed for any reason, reset ride
height using BMW scan tools DIS or
MoDiC.
- Remove spare tire.
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Rear Suspension
4 Remove air line fittings (A) from bottom of air distribution con-
nectors.
Cut off wire ties.
WARNING-
Vehicle will lower when the air pipes are opened.
4 Rotate air line distribution connector (A) 45" in direction of
arrow to remove.
Rotate electrical connector
(B) 45" in direction of arrow to
remove.
Compress wiring connector locking clips
(arrows) and dis-
connect wiring harness.
< Remove air supply unit mounting fasteners (arrows) and re-
move unit.
- Installation is reverse of removal.
When installing air lines always match line colors.
a After assembly, reset ride height using BMW diagnostic
scan tool DIS.

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330-47
Rear suspension/
Ride height sensor, removing and installing
Hall effect sensors for vehicle height detection are mounted
on the
left and right sides of the rear suspension. A coupling
rod mounted between the rear suspension arm and the sen-
sor arm is used to send a varying voltage signal to the
EHC
control module.
Raise car and support safely.
WARNING-
Male sure the car is firmly supported on jaclc stands de-
signed
for the purpose. Place jaclc stands underneath struc-
tural chassis points. Do not place jaclc stands under
sus~ension Darts.
Working underneath rear of car, remove trim panel (arrow)
just ahead of suspension subframe.
Disconnect electrical harness connector from sensor.
4 Remove control rod mounting nut (arrow).Turn control rod to
access sensor mounting fastener.
- Remove sensor mounting fasteners.
- Remove ride height sensor.
- Installation is reverse of removal.
Make sure sensor lever points outward. After assembly, re-
set ride height using BMW diagnostic scan tool DIS.
Tightening torques
Ride
height sensor to bracket 5 Nrn (44 lb-in)
Lever to height sensor
9 Nrn (80 ib-in)

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33UFinal Drive
General ........................... ,331 -2 Drive Axles ....................... 331 -1 4
Special tools
........................ ,331 -2 Drive axle assembly ................. 331-14
Aluminum suspension components
...... ,331-4 Drive axle, removing and
installing (sedan)
.................... 331-14 ........................ Final Drive ,331 -5
Drive axle, removing
........... ...... Final drive, removing and installing ,331-5 and (Sport Wagon) 331-15
...................... Differential oil level, checking ........... ,331-6 CV joint boots 331-17 Final drive in~ut shaft seal, replacing ..... ,331-7 .
Final drive oitput shaft seals, replacing . . ,331-10
Final drive cover, removing and installing ,331-12
Final drive mounts, replacing .......... ,331-12

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331-4
Final Drive
4 Final drive output shaft seal tool
(Tool No.
BMW 33 4 250)
4 Pulling set
(Tool No.
BMW 33 4 401 / 33 4 402 / 33 4 403 133 4 404 /
33 4 405 / 33 4 406)
Aluminum suspension components
In order to reduce vehicle weight, aluminum suspension com-
ponents are
~sed in some models. A tesl wlh a magnet wi.1
eas'ly reveal lhe metal Lseo. If working with a umin~m com-
ponents, be sure to read and follow the cautions below.
CAUTIOI\C
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.

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Final Drive
Final drive, removing and installing
- Raise rear of car.
WARNING-
Make sure that the car is firmly supported on jack stands de-
signed for the purpose. Place the jaclc stands beneath struc-
tural chassis
~oints. Do not i lace iaclc stands under
( suspension barfs.
Remove exhaust system. See 180 Exhaust System.
Disconnect drive shaft from final drive. See
260 Driveshaft.
Remove drive axle CV joint bolts (arrows) at left and right
sides. Suspend drive axles from body using stiff wire.
4 Support final drive with BMW special tool 33 4 390.
* Remove front final drive mounting bolt.
Remove rear final drive mounting bolts
(2).
Carefully lower final drive unit.
- To install, use BMW special tool 33 4 390 to lift final drive into
place.
CA UTIOP&
The following sequence must be used when installing the fi-
nal drive to prevent torsion stress on the final drive during in-
Install mounting bolts and finger tighten only.
Remove final drive support.
Tighten both rear mounting bolts.
Tighten front mounting bolt.
NOTE-
Use new self-locking nuts.
- Check differential oil level. See Differential oil level, check-
ing.
- Remainder of installation is reverse of removal.

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Final Drive
Drive axles use constant-velocity (CV) joints on both ends.
For replacement parts, only CV joint boots or complete axles
are offered by BMW. The procedure for drive axle removal
varies for sedan and sport wagon. Follow the appropriate pro-
cedure below.
Drive axle assembly
1. lnner CV joint
2. Drive axle
3. Outer CV joint
4. Collar nut
5. Outer CV boot kit
6. lnner CV boot kit
7. Circlip
8. Dust cover
9. Reinforcement
10. Torx bolt
Drive axle, removing and installing (sedan)
4 With an assistant applying brakes, break free staked collar
nut (arrow) at center of rear wheel hub. Do not remove com-
pletely.
NOTE-
The drive flange collar nut is tightened to a torque of over 300
Nm (221 ft-lb). Male sure the car is firmly on the ground.
- Raise rear of car. Remove rear wheel
WARNING -
Make sure that the car is firmly supported on jack stands de-
signed for the purpose. Place the
jack stands beneath struc-
tural chassis points. Do not place jack stands under
suspension parts.
- Remove f~nal drrve. See Final drive, removing and install-
ing.