Stationary vehicle during "revving engine"
uphill
Downhill
Whilst driving
Rolling vehicle
Acceleration
Deceleration

Speed:________

km/h

Speed:________

mph

Engine speed:________ Rpm

Which gear(s)?______________
☐ Recurring

☐ Sporadic

4: Weather conditions when the interference occurs?
Outdoor temperature:_______°C
☐ Dry road
☐ Wet road
5: What type of road surface?
________________________________________
6: Vehicle status?

☐ Cold
☐ Hot

TJ Instruction T9379

Page 3 (3)

3.

Further questions
7: Engine temperature?

_____________°C

8: If there is a sound file, where is it recorded?
☐ In the passenger compartment, front seat
☐ In the passenger compartment, rear seat
☐ Under the vehicle
☐ In the engine compartment
Describe at what second the noise is heard.________Sec?
9: Has Chassis-ear, 9814108, been used for fault tracing?
☐ Yes
☐ No
10: What type of recording equipment has been used?

_____________________

11: Space for further comments.
_________________________________________________________________________________________
_________________________________________________________________________________________

TJ 20803
Vibrations in SPA cars
at constant speed and moderate acceleration
(mainly 80 - 135 km/h)
Issuer:
CMQ NVH Quality
Lisette Hey
2017-10-06

TJ 20803

1

First tests
If none of the tests helps, submit a report to technical helpdesk.

Make sure to perform the test drive on a smooth, straight and dry road.
Make sure all tires have correct pressure.
Make sure to drive the car 15 minutes before judging, to avoid flat spot contribution.

2017-10-06

TJ 20803

2

Front wheel driven car (incl. hybrid)
Before the test
tires
Check the status
of the wheels
regarding wear,
damage, dirt, tire
pressure

Drive the
car at least
15 minutes
to get rid of
the flat spot

Lift the car directly after
the 15 minutes’ drive or
demount the tires and
store them flat if you
don’t continue working
with the car directly.

Mass balance all tires
Check force variation
and match tire to rim if
possible and necessary.

1 The

production requirement regarding force variation
is set for a tire pressure of 3.0 bar.
It is 105 N for S90/V90 20”, 90 N for V90CC and
120 N for all other vehicles and tires.
If the force variation value is higher than that, the tire is
not up to specification and has to be replaced.
2 The

requirement for a complaining customer,
however, is 65 N at comfort pressure. The reason for
that is, that a customer, who complains about vibration
problems is (becoming) more sensitive to exactly these
vibrations. He/She would still complain with an “up to
spec” force variation.

2017-10-06

TJ 20803

Replace all tires with a
force variation that is
out of production
specification. 1
Hint: Mount the tires with the
lowest force variation on the front
axle.

Analyse and report

not ok

If the force variation is higher than
65 N, measure force variation again 2
and save the measurement values:
1. with correct pressure
2. with a tire pressure of 3.0 bar

Test drive the car.

ok
claim tires which are out of
production specification to
the supplier

send all values to
technical helpdesk

3

All wheel driven car
tires
Before the test
Check the status
of the wheels
regarding wear,
damage, dirt, tire
pressure

Drive the
car at least
15 minutes
to get rid of
the flat spot

1

Mass
balance
all tires

Check force
variation and match
tire to rim if possible
and necessary.

Remove the propeller shaft.
Remove the DEM fuse.
Test drive. 3

2

Order and mount a new assembly of
companion flange and torsional
damper 4 and test drive (without
propeller shaft and DEM fuse).
4

TJ 20803

If both paths are checked
and the car is still not ok:
ok

Analysis and report

Test drive the car.

Propeller shaft

(active on demand coupler)

ok

If the force variation is
higher than 65 N,
measure force variation
again 2 and save the
measurement values:
1. with comfort pressure
2. with a tire pressure of
3.0 bar

(all wheel drive)

AOC

Companion flange
and torsional damper

Set back DEM
fuse and test
drive (without
propeller shaft).

ok

Order a
new
propeller
shaft.

send all values to
technical helpdesk

not ok
Order and
mount a new
AOC.

see VIDA, depending on chassis

ok

2017-10-06

Hint: Mount the tires with the lowest force
variation on the front axle.

AWD system

not ok

Lift the car directly after
the 15 minutes’ drive or
demount the tires and
store them flat if you
don’t continue working
with the car directly.

Replace all tires with a force
variation that is out of specification. 1

3

ok

ok

to make sure that the AWD system really has no
contribution, this test drive has to be done with a
companion flange without damper. This part is no
longer possible to order. If the test wants/needs to be
done anyway, it is possible to press the damper out
and test drive only with the flange. It is recommended
to order a new assembly after that test to ensure that
it is well balanced.

4

If the car is still vibrating...
If the car is still vibrating, send a report to technical helpdesk.
The report has to include:
 T9379
 Which problem does the customer experience?
 What work has been done so far?

 Numbers of the force variation measurement of the Hunter machine
(including tire pressure)

2017-10-06

TJ 20803

5