Infiniti M35/M45 Y50. Manual - part 998

NOISE, VIBRATION AND HARSHNESS (NVH) TROUBLESHOOTING

PS-7

C

D

E

F

H

I

J

K

L

M

A

B

PS

NOISE, VIBRATION AND HARSHNESS (NVH) TROUBLESHOOTING

PFP:00003

NVH Trouble Shooting Chart

NGS000D4

Use chart below to help you find the cause of the symptom. If necessary, repair or replace these parts.

×

: Applicable

Reference page

PS-

8

PS-

8

PS

-2

4

PS

-2

4

PS

-2

4

PS-

8

PS

-1

0

PS

-1

0

E

M-1

6

,

EM

-174

PS

-1

0

—

PS

-2

3

PS

-1

6

PS

-1

3

PS

-2

1

NVH in

 PR s

e

c

tio

n

 

NVH 

in

 RFD s

e

c

tio

n

NVH i

n

 F

AX, 

RAX

, FSU,

 RSU 

s

e

c

ti

o

n

 

NVH in

 W

T

 s

e

c

tio

n

NVH in

 W

T

 s

e

c

tio

n

 

NVH 

in

 F

AX s

e

c

tio

n

NVH in

 BR s

e

c

tio

n

Possible cause and SUSPECTED PARTS

F

lui

d l

e

vel

A

ir

 i

n

 hyd

rau

lic sys

te

m

O

u

te

r sock

et

 ba

ll j

o

in

t sw

ingi

ng t

o

rq

u

e

O

u

te

r sock

et

 ba

ll j

o

in

t r

o

ta

ti

ng t

o

rque

O

u

te

r sock

et

 ba

ll j

o

in

t end pl

ay

S

teer

in

g f

lui

d l

e

a

k

age

S

teer

in

g w

h

eel

 p

la

y

S

teer

in

g 

gear

 r

a

ck

 s

lid

ing 

fo

rc

e

D

ri

v

e bel

t l

oos

enes

s

Im

pr

oper

 s

te

e

ri

ng 

w

h

e

e

l

Im

pr

oper

 i

n

s

ta

lla

ti

o

n

 o

r l

o

ose

ness

 of

 t

ilt

 l

o

ck l

e

ver

M

o

u

n

ti

ng

 r

ubb

er

 det

er

io

ra

ti

on

S

teer

in

g col

u

m

n

 def

or

m

a

ti

on or

 da

m

a

ge

Im

pr

oper

 i

n

s

ta

lla

ti

o

n

 o

r 

lo

ose

ness

 of

 st

eer

in

g

 c

o

lu

m

n

S

teer

in

g l

inka

ge l

o

osen

ess

P

R

OPE

LLER SHAFT

DIFFERENTIAL

A

X

LE and SUSPENSION

TI

R

E

S

ROAD W

H

EEL

DRIVE SHAFT

BR

AK

E

S

Symptom

Steering

Noise

× × × × × × × × ×

× × × × × ×

×

Shake

×

×

×

× × × ×

×

Vibration

×

× × ×

×

× ×

×

Shimmy

×

×

×

× × ×

×

Judder

×

×

× × ×

×

PS-8

POWER STEERING FLUID

POWER STEERING FLUID

PFP:KLF20

Checking Fluid Level

NGS000D5

●

Check fluid level with engine stopped.

●

Make sure that fluid level is between MIN and MAX.

●

Fluid levels at HOT and COLD are different. Do not confuse
them.

CAUTION:

●

The fluid level should not exceed the MAX line. Excessive
fluid will cause fluid leakage from the cap.

●

Do not reuse drained power steering fluid.

●

Recommended fluid is Genuine Nissan PSF or equiva-
lent.

Checking Fluid Leakage

NGS000D6

Check hydraulic connections for fluid leakage, cracks, damage,
looseness, or wear.

1.

Run engine until the fluid temperature reaches 50 to 80

°

 C (122

to 176

°

F) in reservoir tank, and keep engine speed idle.

2.

Turn steering wheel several times from full left stop to full right
stop.

3.

Hold steering wheel at each lock position for five seconds and
carefully, check for fluid leakage.

CAUTION:

Do not hold the steering wheel in a locked position for more
than 10 seconds. (There is the possibility that oil pump may
be damaged.)

4.

If fluid leakage at connections is noticed, then loosen flare nut and then retighten. Do not overtighten con-
nector as this can damage O-ring, washer and connector.

5.

If fluid leakage from oil pump is noticed, check oil pump. Refer to 

PS-30, "POWER STEERING OIL

PUMP"

 .

6.

Check steering gear boots for accumulation of fluid indicating from steering gear.

Air Bleeding Hydraulic System

NGS000D7

If air bleeding is not complete, the following symptoms can be observed.

●

Bubbles are created in reservoir tank.

●

Clicking noise can be heard from oil pump.

●

Excessive buzzing in the oil pump.

NOTE:
Fluid noise may occur in the steering gear or oil pump. This does not affect performance or durability of
the system.

1.

Turn steering wheel several times from full left stop to full right stop with engine off.

CAUTION:

Filling reservoir tank with fluid so as not to lower fluid level below the MIN line while steering
wheel turning.

2.

Start engine and hold steering wheel at each lock position for 3 seconds at idle to check for fluid leakage.

3.

Repeat step 2 above several times at approximately 3 second intervals.

CAUTION:

Do not hold the steering wheel in a locked position for more than 10 seconds. (There is the possi-
bility that oil pump may be damaged.)

4.

Check fluid for bubbles and while contamination.

HOT

: Fluid temperature 50 - 80 

°

C (122 - 176

°

F)

COLD

: Fluid temperature 0 - 30

°

C (32 - 86

°

F)

PGIA0007J

SGIA0506E

POWER STEERING FLUID

PS-9

C

D

E

F

H

I

J

K

L

M

A

B

PS

5.

Stop engine if bubbles and white contamination do not drain out. Perform step 2 and 3 above after waiting
until bubbles and white contamination drain out.

6.

Stop the engine, and then check fluid level.

PS-10

STEERING WHEEL

STEERING WHEEL

PFP:48430

On-Vehicle Inspection and Service

NGS000D8

CHECKING CONDITION OF INSTALLATION

●

Check installation conditions of steering gear assembly, front suspension assembly, axle and steering col-
umn assembly.

●

Check if movement exists when steering wheel is moved up and down, to the left and right and to the axial
direction.

●

Check steering gear assembly mounting bolts and nut for looseness. Refer to 

PS-19, "COMPONENTS"

 .

CHECKING STEERING WHEEL PLAY

●

Turn steering wheel so that front wheels come to the straight-ahead position. Start engine and lightly turn
steering wheel to the left and right until front wheels start to move. Measure steering wheel movement on
the outer circumference.

●

When the measurement value is outside the standard value, check backlash for each joint of steering col-
umn assembly and installation condition of steering gear assembly.

CHECKING NEUTRAL POSITION STEERING WHEEL

●

Make sure that steering gear assembly, steering column assembly and steering wheel are installed in the
correct position.

●

Perform neutral position inspection after wheel alignment. Refer to 

FSU-6, "Wheel Alignment Inspection"

(2WD), 

FSU-24, "Wheel Alignment Inspection"

  (AWD).

●

Set vehicle to the straight-ahead position and confirm steering wheel is in the neutral position.

●

Loosen outer socket lock nut and turn inner socket to left and right equally to make fine adjustments if
steering wheel is not in the neutral position.

CHECKING STEERING WHEEL TURNING FORCE

1.

Park vehicle on a level and dry surface, set parking brake.

2.

Start engine.

3.

Bring power steering fluid up to adequate operating temperature. [Make sure temperature of fluid is
approximately 50 to 80

°

C (122 to 176

°

F).]

4.

Check steering wheel turning force when steering wheel has
been turned 540

°

 from neutral position.

NOTE:
Multiply the distance (L) from the hook of spring balance to the
center of steering wheel by the measurement value with a spring
balance.

5.

If steering wheel turning force is out of the specification, check
rack sliding force and relief hydraulic pressure of oil pump.
Regarding relief hydraulic pressure of oil pump, refer to 

PS-30,

"CHECKING RELIEF OIL PRESSURE"

 .

a.

Disconnect lower joint and steering knuckle from steering gear assembly. Refer to 

PS-13, "COMPO-

NENTS"

 , 

FAX-5, "COMPONENT"

 .

b.

Start and run engine at idle to make sure steering fluid has reached normal operating temperature.

Steering wheel axial end play

: 0 mm (0 in) 

Steering wheel play

: 0 – 35 mm (0 – 1.38 in)

Steering wheel turning force

: 7.45 N·m (0.76 kg-m, 66 in-lb)

SGIA1615E