Page 637 of 1002

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31 0 Front Suspension
General . . . . . . . . . . . . . . . . . . . . . . . . . . . .310-2 Front Suspension Arms . . . . . . . . . . . 310-1 2
Special tools . . . . . . . . . . . . . . . . . . . . . . . . ,310-2 Control arm, removing and installing
Front suspension variations
. . . . . . . . . . . . ,310-4 (6-cylinder models) . . . . . . . . . . . . . . . . . . 31 0-1 2
Control arm, removing and installing Front Strut ' ' ' ' ' ' ' ' ' ' ' ' ' ' '310-4 ("-8 models) , , , , , , , , , , , , , , , , , , , , , , , 310-13 Front strut assembly, removing
Tension strut, removing and installing . . . . 310-16 and installing . . . . . . . . . . . . . . . . . . . . . . . . ,310-5 Tension strut bushing, replacing . . . . . . . . 310-18 Front strut assembly components
(6-cylinder models)
. . . . . . . . . . . . . . . . . . ,310-9 Wheel Bearings, Front . . . . . . . . . . . . . 310-18
iron; strut assembly, disassembling Front Stabilizer Bar . . . . . . . . . . . . . . . 310-22 and assembling . . . . . . . . . . . . . . . . . . . . . ,310-9 Stabilizer bar, removing and installing . . . . 310-22
Page 638 of 1002

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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)
Page 639 of 1002
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Front Suspension
< Ball joint press
(Tool No. BMW
31 2 240)
< Bushing press tools
(Tool No. BMW
31 2 2611263)
4 Spring compressor and spring holder arms
31 3 350 (Tool No. BMW 31 3 340 131 3 350)
Page 640 of 1002
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31 0-4
I Front Suspension
6-cylinder models
12 3 4 5
V-8 models
16 7 4
Front suspension
variations
1. Steering knuckle
2. Tension strut (thrust arm)
3. Steering rack
4. Front suspension
subframe
5. Outer tie rod
6. Control arm
7. Steering box
8. Idler arm
9. Center tie rod
The front suspension
shoclc absorbers on E39 cars are
MacPherson struts. The strut is a major component of the
front suspension and supports the spring. Most strut assem-
bly components are available as replacement parts. Always
replace struts and springs in pairs.
Front strut, upper strut mount or spring replacement is a two-
step procedure:
Removal of strut assembly from vehicle
Disassembly and replacement of component on
work
bench
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31 0-5
Front ~uspensionl
Front strut assembly, removing and
installing
- Raise car and remove front wheel.
WARNING-
Make sure that 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.
- Unbolt bralte caliper assembly, lkeeping bralte hose connect-
ed. Secure brake caliper to body with wire. Do not let it hang
from brake hose. See
340 Brakes.
Remove ABS pulse sensor mounting bolts (arrows) and re-
move sensor from housing.
Detach ABS sensor wire harness and bralte pad wear sensor
wire harness (if equipped) from strut housing.
Loosen and remove stabilizer bar link mounting nut while
counterholding
link ball joint. Disconnect stabilizer link from
strut.
NOTE-
Use a thin wrench to counterhold shaft of stabilizer bar link
ball joint.
- Cars equipped with vertical headlight adjustment system:
Disconnect control arm from level sensor.
4 Remove outer tie rod end nut. Use BMW special tool 31 2
240 or equivalent to press tie rod end out of steering arm.
Page 642 of 1002
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31 0-6
Front Suspension
Mark installation position of strut tube (arrow) in steering
knuckle pinch collar.
CAUTION--
Use paint, not a scribe tool, to mark location of strut tube. 1
4 Letter on strut tube designates mounting location.
- R - Right side installation position
L - Left side installation position
NOTE-
Marking the strut tube is not necessary if factory marks (L or
R) are still visible.
4 Counterhold strut tube pinch bolt (arrow)
nut. while
loosening
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31 0-8
Front Suspension
Slide strut assembly out of steering lknucltle pinch collar. If
necessary use pry bar.
CA UTIOI\C
Do notpullstrut out of steering knuckle with twisting motion.
This can scratch and damage the strut.
Disassemble and reassemble strut assembly as described
later.
When installing new strut, be sure to align locator letter (A)
on strut body with slot in steering
lknuckle pinch collar (6).
Struts are marked with L for left and R for right.
Remainder of installation is reverse of removal.
Make sure strut shoulder (below locator letter) bottoms out
in steering knuckle pinch collar.
Use new self-locking nuts and bolts.
When attaching stabilizer
lrnk to strut, use a thin wrench to
counterhold
link ball joint while t~ghtening nut.
- Have car professionally al~gned when job IS complete.
Tightening torques
Brake caliper to steering knuckle
110 Nm (81 ft-ib)
Road wheel to hub 120 ti0 Nm (89 t7 ft-lb)
Stabilizer bar
link to strut 65 Nm (48 It-lb)
Steering knucltle pinch bolt at strut 81 Nm (60 It-lb) - mountlng collar
Steering tle rod to steerlng knuckle 65 Nm (48 it-lb)
Strut assembly top to strut tower 24 Nm (18 it-lb)
- - -
Page 645 of 1002
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31 0-9
Front Suspension
Front strut assembly
components
(6-cylinder models)
1. Cap
2. Upper strut self-locking nut
3. Washer
4. Strut bearing reinforcement
5. Strut mount self-locking nut
6. Upper strut mount
7. Dust protector collar
8. Spacer
9. Upper spring seat
10. Spacer
11. Upper spring pad
12. Coil spring
13. Rubber stop
14. Dust boot
15. Lower strut pad
16. Strut with lower spring seat
Front strut assembly, disassembling
and assembling
Replacing the strut, upper strut mount or spring requires that
the strut assembly first be removed from the car
and disas-
sembled. For a guide to parts used during component re-
placement, see the accompanying diagram.
NOTE-
Illustration shows components ior 6-cylinder models (525i,
528i, 530;). V-8 models (540i) are similar but not identical.