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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). - -
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320-7
Steering and Wheel ~liqnmentl
STEERING WHEEL
Steering wheel, removal and installation
WARNING -
The BMWairbag system (Supplemental Restraint System or
SRS) is complex. Special precautions must be observed
when servicing. Serious injury may result if
SRS system serv-
ice is
attempted by persons unfamiliar with the BMW SRS
and its approved service procedures. BMW specifies that all
inspection andservice should be preformed by an authorized
BMW dealer.
E39 cars may come with either one of two different styles of
steering wheel:
Multifunction (MFL) steering wheel
* Sport steering wheel
4 Multifunction (MFL) steering wheel components:
1. Cruise control 1 radio 1 telephone electrical harness
2. Horn button electrical harness
3. Airbag electrical harness
4. Radio / telephone control switch set
5. Air bag
6. Cruise control switch set
Sport steering wheel
3
5 0021413
4 Sport steering wheel components:
1. Switch carrier
2 Steering wheel switch set electrical harness
3. Airbag
4. Lower cover
5. Horn button and airbag electrical harness
- Center steering wheel. Make sure front wheels are pointed
straight ahead.
- Disconnect negative (-) cable from battery.
CA UTIOP&
Prior to disconnecting the battern read the battew discon-
nection cautions given in
001 General Cautions and
Warnings.
-
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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.
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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
-" ., - , . ,
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--. --
Steering and Wheel Alignment
Steering rack boot, replacing
- Remove outer tie rod end. See Tie rod (outer), replacing
- Cut rack boot band clamps and remove boot.
- Cut rack boot band clamp and slide bellows back. Inspect
boot for any sign of damage. Replace
if necessary.
NOTE-
New rack boot lit comes with new band clamp.
- Grease tie rod taper so that small end of rack boot slides on
tie rod when tie rod is tightened, preventing raclc boot from
twisting.
- Slide new boot into position and replace band clamps
Tie rod (outer), replacing
LOCI( nut Locking ring
- Raise front of car. Remove road wheel
WARNING-
Male sure caris firmly suppoiiedon jackstands designed for
the purpose. Place jack stands beneath structural chassis
ooints. Do not olace iack stands under
susoension oaiis.
4 Make reference measurement (A) of outer tie rod end to tie
rod. Record measurement.
NOTE-
Accurate measurement of the tie rod end with reference to
the tie rod will help approximate correct
wheel alignment
when new parts are installed.
Note correct placement of inner taper on
loclcing ring.
Loosen outer tie rod end
loclc nut (arrow).
Remove tie rod lock nut from steering
ltnuclcle.
Press tie rod out of steering knuckle using BMW
31 2 240 or equivalent. special tool
Unscrew tie rod end from tie rod shaft.
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Steering and Wheel ~li~nrnentl
Steering gearbox, removing and installing
- Disconnect negative (-) battery cable. See 020 Mainte-
nance.
CAUTION-
Prior to disconnecting the battew read the battery discon-
nection cautions given in
001 General Cautions and
Warnings.
- Remove airbag unit from steering wheel. See 721 Airbag
System (SRS).
WARNING -
Improper handling of the airbag could cause serious injury
Store the
airbag with the horn pad facing up. If stored lacing
down, accidental deployment couldpropel it violently info the
air, causing
injuv
- Remove steering wheel as described earlier.
- Drain power steering system reservoir.
- Raise front of car.
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 heat shield from left side of subframe.
- Remove fluid hoses from top of steering gearbox. Immedi-
ately plug all fluid openings.
Remove and discard
pitman arm self-loclting nut (arrow).
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320-28
[steering and Wheel Alignment
Pitman arm, removing and installing
- Raise front of car. Remove splash shield from under engine.
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
jaclc stands under suspension
parts.
4 Set steering wheel in straight ahead position with tab (arrow)
aligned with mark on steering gearbox.
Remove center tie rod fastener and press tie rod out of pit.
man arm with BMW special
too1 32 1 190.
- Loosen and remove pitman arm pinch bolt
4 Mark A on steering gearbox shalt must be located in center
of
pitman arm slot.
- Reinstall center tie rod and tighten nut.
- Adjust pitman arm height as described later.
- Have vehicle professionally aligned.
Tightening torques
50:s,n5m Center tie rod to pitman arm 65
Nm (48 ft-lb)
(use new self-locking nut)
Pitman arm pinch bolt (note direction of threads) 61 Nrn (45 ft-lb)
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Steering and Wheel Alignment
Pitman arm, adjusting
As the vehicle suspension settles down, the toe on the left
and right wheels must remain identical for proper handling.
By adjusting the height of the
pitman arm, the left and right tie
rods are moved to the same ride level setting. This will opti-
mize straight-ahead travel on uneven road surfaces.
- Raise front of car. Remove splash shield from under engine.
WARNING-
Male sure the car is iirmly supported on jack stands de-
signed ior the purpose. Place jack stands beneath structural
chassis points. Do not place
jaclc stands under suspension
parts.
- Remove bolts from left and right inner control arm mounts.
Place
BMW special tool 32 2 140 through right side control
arm mounting bolt hole.
Loosen fastener
A and push pin El up so that it is firmly
against tie rod
(arrow). Tighten fastener A.
- Remove tool without disturbing position of pin El.
- Loosen pitman arm clamping bolt and slide arm up.
4 Place special tool 32 2 140 through left side control arm
mounting bolt hole.
Slide
pitman arm up or down until tie rod makes contact
with pin
(El).
Tighten pitman arm clamping bolt.
Tie rod height differences
Deviation between
left and right tie rod height -?-I .5 rnrn (LO6 in)