wheel torque BMW 540i 1998 E39 Repair Manual

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Steerina and Wheel ~lianmentl
Proper handling, stability and driving ease depend upon the
correct alignment of all four wheels. The front axle is aligned
in relation to the rear axle, then the front wheels are aligned in
relation to one another. This is known as a four-wheel or
thrust-axis alignment.
Front and rear alignment specification are given in tables at
the end of this repair group.
BMW E39 cars use a sophisticated multi-link suspension at
the front and rear of the car. Proper alignment requires com-
puterized alignment equipment.
Camber
Front wheel camber is set at the factory and cannot be adjust-
ed. Rear wheel camber is fully adjustable.
Always set rear camber before adjusting toe
Before making rear camber adjustment, install a new rear
control arm mounting nut
(arrow) and tighten.
- Loosen mounting nut one-half to one full turn.
Using eccentric bolt, adjust camber to factory settings.
Tighten nut only after car has been lowered to ground and
suspension has settled.
Tighten nut while counterholding adjustment bolt.
Tightening torque
Camber adjusting nut (rear)
MI2 (sedan)
- MI4 (Sport Wagon)
115 Nm (85 ft-lb)
174 Nm (128 ft-lb)
Caster
Front and rear caster are fixed by the design of the car and
deviations are usually the result of worn or damaged suspen-
sion or body parts.
- Check front suspension arms and bushings for wear, dam-
age and deformation if front caster problems are present.
- Check rear axle subfrarne and traction struts if rear caster
problems are present.

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320-34
I Steerins and Wheel Alignment
Front toe and toe difference angle
Toe is the difference in the distance between the front of the
front wheels and the rear of the front wheels. It is adjusted by
altering the length of the tie rods.
Toe difference angle determines the progressively different
paths taken by the front wheels as the car is turning. In
V-8
models, it is set by the pitman arm adjustment, but depends
on accurate setting of the toe.
Toe adjustments should only be made on specialized align-
ment equipment and only with the car in normal loaded posi-
tion, described below.
- Set front wheel toe at tie rod ends:
4 6-cylinder models: Loosen tie rod lock nut (A).
Adjust toe by turning inner tie rod (B) to change length
- V-8 models: Loosen left and right tie rod clamp bolts.
Adjust toe by turning inner tie rod to change length.
NOTE-
* Steering rack or steering gearbox can be centered by
aligning centering mark on steering shaft
with lug on steer-
ing rack.
To keep steering wheel centered, adjust both tie rods equal
amounts.
&cylinder models: Make sure the rubber boot on the rack
moves freely on the tie rod and does not become twisted.
Tightening torques
Tie rod clamp bolt
Tie rod collar
nut
27 Nm (20 ft-lb)
45 Nm (33 A-lb)
Rear toe
To adjust rear wheel toe, turn eccentric inner mounting bolt in
upper front control arm (traction strut).
NOTE-
Always adjust rear camber first.
- Before making toe adjustment, install new
mounting nut and tighten.
- Loosen nut one-half to one full turn.
4 Turn eccentric bolt (arrow) to adjust toe. rear
control arm

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330-6
Rear Suspension
4 Remove rear strut top cover. Remove upper strut mounting
nuts (arrows).
Remove strut assembly lower mounting bolt (arrow).
Disassemble strut and spring assembly as described below
in Rear strut assembly, disassembling and reassem-
bling.
Installation of assembly to car is reverse of removal, noting
the following:
Make sure all threaded bolts, nuts and mating surfaces are
clean.
Install strut assembly top mount using new self-loclting
nuts.
Malte sure long lower strut bushing fits in
hole in wheel
bearing carrier.
Tightening torques Strut to wheel bearing carrier 127 Nm (94
it-lb)
Strut mount to body
Gray fasteners 28 Nm (21 ft-lb)
Yellow fasteners 24 Nm
( 18 it-lb) -
Road wheel to hub 120ilO Nm (89i7ft-lb)

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330-1 0
/Rear Suspension
- Remove rubber protective cap from shock absorber upper
mount.
- Remove shock absorber upper mounting nuts.
- Remove shock absorber lower mounting bolt. Lower shock
absorber out of wheel housing.
< Transfer shock top mounting plate, dust cover (if applicable)
and related components to new shoclc absorber.
1. Self-locking nut
2. Washer
3. Upper siioclc absorber mount
4. Rubber bumper seat
5. Rubber bumper
6. Dust boot
7. Shock absorber
8. Long lower bushing
Tightening torques
Shock absorber to upper mount
27 Nm (20 it-lb)
(M14, replace self-locking nut)
- Installation on car is reverse of removal, noting the following:
Make sure all threaded bolts, nuts and mating surfaces are
clean.
Install shock absorber upper mount to
subframe using new
self-locking nuts.
. Make sure long lower shock absorber bushing fits in hole
in suspension swing arm.
Tighten lower shoclc absorber bolt to its final torque once
car is on ground.
Tightening torques
Quick coupling screw to air 2 Nm (18 in-lb)
shock absorber
Road wheel to
hub 120 &I0 Nm (89 -f7 ft-lb)
Shock absorber to swing arm 127 Nm (94 ft-lb)
Strut mount to body
Gray fasteners
Yellow fasteners
24 Nm ( 18 it-lb)

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330-1 1
Rear Suspension
Coil spring, removing and installing
Raise car and remove rear wheels.
WARNING-
Make sure the car is firmly supported on jack stands de-
signed for the purpose. Place jack stands underneath struc-
tural chassis points. Do not place jack stands under
suspension parts.
- Remove brake caliper and brake disc. Hang brake caliper
aside with stiff wire. Do not disconnect
bralte fluid hose. See
340 Brakes.
- Remove exhaust system. See 180 Exhaust System.
- Disconnect driveshafl from final drive. See 260 Driveshaft.
- Detach parking bralte cables from mounting bracltets on sub-
frame.
< Support final drive unit from below using transmission jack
and
BMW special tool 33 4 390 or equivalent.
Remove rear suspension
subframe mounting bolts (arrows).
Lower rear
subframe until coil springs can be removed.
When reinstalling springs, replace upper and lower spring
pads if necessary.
Slowly lift suspension
back into position, making sure coil
springs are correctly seated in upper and lower spring seats.
Install and tighten
subframe mounting bolts. Note that on
each bolt, rubber-coated detent plate (arrow) must be in-
stalled at rear in driving direction
- Remainder of installation is reverse of removal
Tightening torques Road wheel
to hub 12OilO Nm (89i-7 ft-lb)
Subframe to body 163 Nm (120 ft-lb)

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Rear Suspension
Air spring, removing and installing
CAUTION-
If vehicle is driven with airspring depressurized, the airspring
will be permanently damaged and must be replaced.
An air spring is made from a flexible rubber material which
forms an airtight cavity. It is pressurized by an air supply
pump activated by an electronic control unit to provide a
vari- . . able spring rate depending on vehicle load
CAUTIOIG
Disable air supply pump by disconnecting electrical plug
before performing any repairs. Pump is located beneath a
cover under the spare tire in the floor of
the cargo compart-
ment.
When removing and installing air connections, extreme
cleanliness must be followed. Small dirt particles can
cause leakage in the system.
Remove luggage compartment floor mat.
- Working above air spring, loosen quick coupling screw con-
nection to allow
air pressure to escape.
- Once pressure has been reduced, retighten screw.
Tightening torque Quick coupling screw
to air pump 2 Nm (18 in-lb)
- Remove quick coupler. Plug openings to keep dirt out,
- Remove air spring mounting clips.
- Raise car and remove rear wheels.
Make sure the car is firmly supported on jack stands de-
signed for the purpose. Place jack stands underneath struc-
tural chassis points. Do not place
jaclc stands under
suspension parts.
- Working underneath rear suspension, lift wheel bearing car-
rier to relieve rear spring tension. Then unbolt air spring
mounting bolt from seat on wheel bearing carrier. Remove air
spring.
NOTE-
Left and right air springs are different. The left air spring is
marked with a red identification
marl. The right air spring is
marked with a blue identification mark.

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330-1 3
Rear Suspension
1 1 4 Check roll fold of air spring (arrows). Reinstall only if roll fold
is undamaged and formed correctly.
- To install air spring:
Check sealing O-rings at air spring inlet. Replace
if dam-
aged. Do not grease O-rings. Reinstall protective plug.
* Install spring above suspension subframe. Make sure ec-
centric lug at bottom of air spring fits in recess of
subframe
spring seat.
Reattach top spring mounting clips.
- Reattach air line connections.
- Remainder of installation is reverse of removal.
Tightening torques
Air line connection
2 Nm (1 8 in-lb)
Air spring
to wheel bearing carrier 20 Nm (1 5 ft-lb)
Road
wheel to hub 120 510 Nm (89-F-7 ft-lb)
REAR SUSPENSION ARMS,
SUBFRAME AND BUSHINGS
A damaged suspension arm orworn bushings will change the
rear wheel alignment and may adversely affect handling and
stability.
WARNING-
Do not attempt to straighten a damaged suspension arm.
Bending or heating may
weaken the original part. Always re-
olace a damaoed susoension arm.
Rear suspension arm
components
1. Eccentric washer
(for rear toe adjustment)
2. Upper front control arm
(guide link or traction strut)
3. Outer swing arm bushing and
integral link
4. Swing arm (lower control arm)
5. Upper rear control arm
(wishbone)
6. Wheel bearing carrier
7. Circlip
8. Swing arm ball joint
9. Eccentric washer
(rear camber adjustment)

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--- .-
Rear ~us~ensionl
Remove fasteners A, B and C while supporting swing arm
from below.
Carefully pry swing arm away from mounting points, while
continuing to support from below.
Remainder of installation is reverse of removal, noting the fol-
lowing:
Use new self-locking nuts.
lnstall bolt
(C) through bracket and arm. Install and tighten
nut finger tight.
Install bolts
(A) and (6). Install and tighten nuts finger tight.
Line up eccentric camber adjusting bolt with marlts made
previously.
Tighten fasteners to final torque only after vehicle has
been lowered and suspension has settled.
Have car professionally aligned when job is complete.
Tightening torques
ABS pulse sensor to wheel bearing carrier 8 Nm (6 ft-lb)
Road wheel to hub
120+10 Nm
(89
i-7 ft-lb)
Stabilizer link to swing arm 65
Nm (48 ft-lb)
Swing arm to rear
subframe
(camber bolt M12) (A)
115 Nm (85 ft-lb)
Swing arm to rear
subframe (B) 58 Nm (43 ft-lb)
Swing arm
to wheel bearing carrier (C) 256 Nm (189 ft-lb)

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--. -
Rear Suspension
Remove fasteners A. B and C while supporting swing arm
from below.
Carefully pry swing arm away from mounting points, while
continuing to support from below.
Remainder of installation is reverse of removal, noting the fol-
lowing:
Use new self-locking nuts.
Install bolt
(C) through bracket and arm. Install and tighten
nut finger tight.
lnstall bolts (A) and
(6). Install and tighten nuts finger tight.
Line up eccentric camber adjusting bolt with rnarlts made
previously.
Make sure long lower shock absorber bushing fits in hole
in swing arm.
Tighten fasteners to final torque only afler vehicle has
been lowered and suspension has settled.
Have car professionally aligned when job is complete.
Tightening
torques
ABS pulse sensor to wheel bearing 8 Nm (6 It-lb)
carrier
Quiclc coupling screw to air shock 2 Nm (18 in-lb)
absorber
Road wheel to hub 120
210 Nm (89i-7 It-ib)
Shocic absorber
to lower control arm 127 Nm (94
ft-lb)
Stabilizer link to swing arm
65 Nm (48 ft-ib)
Swing arm to rear
subframe (camber 11 5 Nm (85 It-lb)
bolt M12) (A)
Swing arm to rear subframe (6) 58 Nm (43 It-lb)
Swing arm to wheel bearing carrier 256
Nm (189 It-lb)
(C)

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330-22
I Rear Suspension
s
4 If necessary, machine special tool 33 4 191 as shown.
NOTE-
Slotted end of special tool 33 4 191 points toward wheel
bearing carrier.
Press new bushing into wheel bearing carrier using BMW
special tools
33 4 191,33 4 192,33 4 194 and 33 3 333 until
bushing collar is flush with carrier (arrows).
- Install new snap ring
- Reassembly is reverse of disassembly
Use new self-locking nuts.
Tighten fasteners to final torque only after vehicle has
been lowered and suspension has settled.
Tightening torques Integral link to wheel bearing carrier 105
Nm (77
ft-lb)
Quick coupling screw to air shock 2
Nm (18 in-ib)
absorber
Road wheel to hub
120+lO Nm (89c7ft-ib)
Shock absorber to lower control arm 127 Nm (94 ft-lb)
Stabilizer link to swing arm 65
Nm (48
fl-lb)
Swing arm to wheel bearing carrier (C) 256 Nrn (189 ft-lb)
Upper rear control arm, removing and
installing (sedan models)
- Raise rear end of car and remove wheel.
WARNING-
Make sure the car is firmly supported on jack stands de-
signed for the purpose. Place jack stands underneath struc-
tural chassis points. Do not place
jaclc stands under
suspension parts.