Steering System - General Inform
ation - Steering System
D
iagnosis and Testing
I
nspection and Verification
1.
1. Verify t
he customer concern by driving the vehicle.
2. 2. Visually inspect for obvious signs of mechanical or electrical damage.
Mec
hanical Inspection Chart
Electrical Inspection Chart
Mechanical Checks
Incorrect
tire pressure, loose whee
l nuts, incorrect wheel alignment
Loose ti
e-rods
Loose dam
per and spring assemblies or ball joint
Loose s
teering column shaft universal joints
Loose pinc
h bolts on steering column shaft
Loose steeri
ng gear assembly
Check f
or external damage to the steering gear.
- Damaged tie-rods
-
CAUTION: If a steering gear assemb ly is returned under warranty with leaking seals, but there is also
damage to the steering gear boot/boots the steering gear warranty will be invalid. This is due to the steering
gear seals being damaged due to fore ign materials entering the steering gear boot and damaging the steering
gear seals thereafter.
Damaged steering gear boot
Damaged accessory driv
e belt
Bin
ding or misaligned steering co
lumn, pump or steering gear
Incorrect fluid
level
Hose leaks o
r line restrictions
Hose fou
ling bodywork
El
ectrical Checks/Tests
Make sure all
connectors are in plac
e (steering gear Servotronic solenoid and steering control module (SCM) - if
applicable)
Make su
re all the fuses are in place and not blown
D
ISCONNECT the steering gear transducer
and the steering should become heavy
TEST e
lectrical values:
- Power Supply to the SCM = 12 Volts
- Steering gear transducer resist ance 7.0 to 7.5 Ohms is normal
(
limits: less than 5 Ohms and greater than 9 Ohms would
be declared unacceptable)
- Steeri
ng gear transducer voltage = 6 Volts
- Steering gear transducer cu rrent = 840 mA at 0 mph reducing to 0 mA at maximum speed
3.3. If an obvi
ous cause for an observed or
reported concern is found, correct th e cause (if possible) before proceeding
to the next step.
4. 4. Check the power steering fluid condit ion. For additional information, REFER to Power Steering Fluid Condition
Check in this section.
5. 5. If the concern is not visually evid ent, verify the symptom and REFER to Steering Fault Diagnosis by Symptom
Charts in this section.
Steering Re
lay Harness Connector
Stee
ring Linkage In
spection and Backlash (Freeplay) Check
CAUTIO
N: Steering gear boots must be
handled carefully to avoid damage. Use new clamps when installing steering
gear boots.
Inspect the boots for cuts, deterioration, tw isting or distortion. Check the steering gear boots to make sure they are tight.
Install new boots or clamps as necessary.
REC O
NNECT all electrical item
s disturbed during testing
Ite
m
De
scr
iption
1Ste
e
rin
g tran
sduc
er
ground
2Igni
ti
on feed
3Steeri
ng transducer feed
4Ground
5Speed s
ensor signal
6Seri
a
l interface
Function
al
Fl
uid
leakage
O
verfilled system.
CORRECT the
fluid leve
l as necessary.
Compon
ent leak.
•
NOTE: Record the position of the le
ak and some indication of the rate
of the leak on the Warra nty Return Record Sheet.
LOCATE
the suspect component or CHECK hose connections and
repair as necessary.
Damaged fluid cap. INST
ALL a new fluid cap.
Loose or damaged h
ose
fittings.
TI
GHTEN or INSTALL a new hose as necessary.
Leakage at
power
steering pump.
INST
ALL a new power steering
pump as necessary. For
additional information,
REFER to Section 211
-0
2 Power Steering
.
Fl
uid
leakage
Leakage
at steering hose
to steering gear connection.
CHECK
steering hose to
steering gear conn ection for leakage.
CHECK and TIGHTEN the steeri ng hose to steering gear
connection retaining bolt s/bolts as necessary.
Power steeri
ng fluid
leakage at O-ring seals.
CHECK
the power steering system fo
r signs of steering fluid loss
from O-ring seals.
INST
ALL new O-ring seals as necessary.
BLEE
D the power steering system.
For additional information,
REF
ER to Section 211
-0
0 Steering System
- Ge
neral
Informati
on
.
Power steeri
ng fluid
leakage from transfer pipes.
CHECK
the power steering system fo
r signs of steering fluid loss
from the transfer pipes.
CHECK
and TIGHTEN the transfer pipes if required, INSTALL new
transfer pipes as necessary.
BLEE
D the power steering system.
For additional information,
REF
ER to Section 211
-0
0 Steering System
- Ge
neral
Informati
on
.
Power steeri
ng fluid
leakage from the steering
gear.
CHECK
the power steering gear for signs of fluid loss.
INST
ALL a new steering gear as
necessary. For additional
information,
REFER to Section 211
-0
2 Power Steering
.
Power steeri
ng fluid
leakage from steering gear boot.
CHECK
the power steering gear for signs of fluid loss.
INST
ALL a new steering gear as
necessary. For additional
information,
REFER to Section 211
-0
2 Power Steering
.
Cond
ition
Possib
le Sources
Acti
on
F
ree play at steering wheel
Exce
ss play in the steering
linkage.
CHECK
the steering linkage for excess play.
For additional information, REFER to the
Steering Linkage Inspection and Backlash (Freeplay) Check in this section.
S
teering wheel loose.
CHECK
and TIGHTEN the steering wheel
retaining bolt/bolts as necessary. For additional information,
REFER to Section 211
-0
4 Steering Column
.
Lower steeri
ng column
pinch bolt loose.
CHECK
and TIGHTEN the lower steering
column pinch bolts as necessary. For additional information,
REFER to Section 211
-0
4 Steering Column
.
Exce
ssive wear in lower
steering column.
CHECK
for lower steering column for wear in
the universal joints. If wear is present,
INSTALL a new lower steering column as necessary.
W
ear in suspension joints.
CAU
TION: DO NOT attempt to adjust the
steering gear yoke. Failure to follow this instruction
will result in the steering gear warranty to become
invalid.
CHECK
for excess wear in the front
suspension joints. For additional information,
REFER to Section 204
-00
Suspension
Sy
stem
- General
Information
.
Buzz (E
lectrical)
A
different steering buzz can be caused by
pulse width modulated (PWM) electric actuators used in variable assist steering
systems. This buzz is felt by turning the ignition key to run without starting the engine and holding onto the steering wheel.
In extreme cases, the buzz can be felt with the engine running also.
Column/Steering Wheel
Shake
Column shake is a low f
requenc
y vertical vibration excited by primary engine vibrations.
Nibble (Shimm
y)
Steeri
ng nibble is a rotary oscillation or
vibration of the steering wheel, which can be excited at a specific vehicle speed.
Nibble is driven by wheel and tire imbalance exciting a suspensi on recession mode, which then translates into steering gear
travel and finally steering wheel nibble.
Shudder (Judd
er)
Shudder i
s a low frequency oscillation of th
e entire steering system (tire, wheels, st eering gear and linkage, etc.) when the
vehicle is steered during static-park or at low sp eeds. Shudder is very dependent on road surface.
Torque Ri
pple
Torque rippl
e is a concern with Electric Power Steering (EPS) sy
stems. Torque ripple is most evident at static-park steering
the wheel very slowly from lock to lock. Torque ripple is primarily caused by motor commutation.
Torque/Veloc
ity Variation
(Phasing/Effort Cycling)
Steeri
ng wheel torque variation oc
curring twice in one revolution is normally as a result of problems with the lower steering
column (intermediate shaft), but foul cond itions generally result in either constant stiffnes s or single point stiffness.
Depending upon the orientation of the joints, the steering can fe el asymmetric (torque falling off in one direction and rising
in the other) or else it can simply have pronounced peaks and troughs as the steering moves from lock to lock.
Wheel Fight
(Kick Back)
W
heel fight is excess feedback of sudden road forces through th
e steering system and back to the driver. It is evaluated at
all vehicle speeds over cobblestones, rough roads, and potholes . The tires, wheels, and suspension generate forces into the
steering systems. Steering friction, hydraulic damping, hydr aulic compliance, mechanical compliance, steering ratio, and
assist gain all affect how much is transmitted to the driver.
Stee
ring Linkage
CAUTI
ON: Steering gear boots must be
handled carefully to avoid damage. Use new clamps when installing steering
gear boots.
Inspect the boots for cuts, deterioration, tw isting or distortion. Check the steering gear boots to make sure they are tight.
Install new boots or clamps as necessary.
• NOTE: The following steps must be carried out with assistance.
1. 1. With the wheels in the straight ahead po sition, gently turn the steering wheel to the left and the right to check for
free play.
2. 2. Free play should be between 0 and 6 mm (0 and 0.24 in) at the steering wheel rim. If the free play exceeds this
limit, either the ball joints are worn, the lower steering column joints are worn or the backlash of the steering gear
is excessive.
The lower steeri ng col
umn:
Is a han
ded assembly
.
Incorporates
a col
umn to toeboard seal
which comprises a rolling element having two, low friction, PTFE rings. The
rolling element locates in a rubber b oot which seals to the toeboard.
Has a lowe
r universal joint connecting the
lower column to the steering rack.
Has an upper un
iversal joint connecting
the lower column to the upper column.
Has a NVH damper in
corporated into
the upper universal joint assembly.
May be installed in an
y orientation on the universal joint splines.
R
e
quires no setting or adjustment.
Has no s
e
rviceable components.
It is essential to disconnect the lower column from the steer ing rack before removing the engine or front suspension
crossbeam.
It e
m
Par
t
Number
De
scr
iption
1-Boot
2-Uni
v
ersal joint to upper column
3-Lower steeri
ng col
umn shaft
4-R
e
taining bolts
5-Uni
v
ersal joint to steering rack
Lower Steering Column
Steering Column - Steering Colu
mn Lower Shaft
Re
moval and Installation
Remov
al
1.
Raise
and support the vehicle.
For additional informat ion, refer to Section 100
-0
2 Jacking and
Liftin
g
.
2. De
tach the steering
column lower shaft.
1. Loosen the steering column lower shaft sliding joint retaining bolt.
2. Remove and discard the st eering column lower shaft
retaining bolt.
3. Detach the steering column lower shaft.
3. Lower the vehicle.
4. Remove an
d discard the steering
column lower shaft retaining
bolt.
5. De
tach the steering
column lower shaft.
6. Remove the steering column lower shaft.
De
tach the boot.
In
stallation
1.
CAUTIO
N: Make sure the boot
is fully seated at the top
and bottom.
Attach the boot.
2. CAUTI O
NS:
Make sure the steering column lower shaft rolling element
is fully seated into the boot.
Make sure the boot is fully seated at the top and bottom.
Install the steering column lower shaft.
3. CAUTI O
NS:
Make sure the steering column lower shaft is fully installed
to the steering column shaft splines.
Make sure the steering column lower shaft rolling element
is fully seated into the boot.
Attach the steering column lower shaft.
4. WARNING: In stall a new stee ring column lower shaft
r
etaining bolt. Failure to follow this instruction, may result in
personal injury.
the pipes. Allow the oil to drain.
3. Remove the O-ring seals and fit blanking plugs to the
pipes and to the mating unions on the engine.
51. Lower the ramp.
52. Disconnect the generator suppres sion module (where fitted)
harness.
Disconnect the harness multi-plug and reposition the
harness from under the suppression module.
53. Disconnect the starter motor power cable, at the right hand
side engine compartment enclosure.
1. Disconnect the multi-plug, engine management harness to starter motor.
2. Reposition the protective boot from the starter motor
power stud.
3. Remove the nut and disc onnect the power cable.
Cut the tie strap which secures the power cable to the
enclosure and route the cable into the engine bay.
54. Disconnect the P.I. harness from the engine management
harness.
1. Release the bolt which secures the P.I. harness multi-plug to the engine management harness.
2. Disconnect the multi-plug.
3. Remove the nut which secures the engine management harness multi-plug to the mounting
bracket.
4. Reposition the multi-plug from the bracket.
55. Disconnect the transmission rota ry switch harness connector.
Reposition and disconnect the harness multi-plug.