SERVICE BULLETIN
SB1709
ADDRESSEES

: Owners and operators

VEHICLE MODEL

: All vehicles with light-alloy wheels

MANUAL CHAPTER

: 12.06 Front axle – wheel hub
12.10 Drive axle – wheel hub
12.14 Trailing axle – wheel hub

BULLETIN TYPE

: Product improvement

DATE

: August 31st, 2022

SUBJECT

: Introduction of wheel-end monitoring system (WEM)

TERMS & CONDITIONS

: This product improvement does not entitle to any
reimbursement.

DESCRIPTION
Van Hool has released a wheel-end monitoring system (WEM) which can be installed on all
vehicles equipped with light-alloy wheels. The WEM is installed at the outboard side of the wheel
and monitors vibrations produced by the wheel bearing. It warns in case of bearing raceway
spalling by flashing a red LED on the unit. The WEM is delivered with a magnet which is used to
change from “transport” to “standstill” mode.

Figure 1: Wheel-end monitoring sensor
with mounting plate (WEM)

CHECKING WHEEL BEARING CONDITION
The LED on the WEM indicates the bearing condition.




GREEN: wheel bearing condition OK
RED: damage detected
GREEN AND RED: WEM malfunction

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INSTALLATION ON 8.25”/9” FRONT AXLE WHEELS AND 8.25”/9” SINGLE
MOUNTED TRAILING AXLE WHEEL
Because the WEM comes together with a mounting plate, special sleeved flange nuts
VH11469307 are allowed to compensate the thickness of the mounting plate. Compared with the
originally installed wheel nut VH10516438, nut VH11469307 is threaded all the way up (refer to
figure 3). To avoid wheel nut mixture during installation, Van Hool has decided to enlarge the kit
with two compensation plates and ten wheel nuts VH11469307 so that the wheel has all around
the same wheel nuts.

Figure 2: Installation of WEM on front axle wheels and
single mounted trailing axle wheels (8.25” and 9”)
1.
2.
3.

Figure 3: Difference between wheel nuts 10516438
and 11469307

Compensation plate
WEM sensor with mounting plate
Wheel nut 11469307

INSTALLATION ON 10.5” FRONT AXLE WHEELS AND 10.5” SINGLE MOUNTED
TRAILING AXLE WHEEL
The thread of the originally installed wheel nuts is long enough to compensate the thickness of the
sensor mounting plate.

Figure 4: Installation of WEM on 10.5”
wheels
1. WEM sensor with mounting plate
2. Originally installed wheel nut

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INSTALLATION ON 8.25”/9” DRIVE AXLE WHEELS AND 8.25”/9” DUAL MOUNTED
TRAILING AXLE WHEELS
The thread of the originally installed wheel nuts is long enough to compensate the thickness of the
sensor mounting plate.

Figure 5: Installation of WEM on drive
axle wheels and dual mounted trailing
axle wheels (8.25” and 9”)
1.
2.

WEM sensor with mounting plate
Wheel nut 10941058

INSTALLATION ON STEEL WHEELS
The installation of a WEM on steel wheels is not allowed because the threads of the wheel nuts

cannot compensate the thickness of the mounting plate.

Figure 6: Installation on steel wheels
is not allowed!

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COMPONENTS
Wheel-end monitoring sensor with mounting bracket (WEM) only
VH reference Description
11718941
Wheel-end monitoring sensor with mounting bracket (WEM)

Quantity*
1

*Quantity suited for one wheel-end

Parts of retrofit kit VH11725750 (= kit with wheel-end monitoring sensor!)
(for 8.25”/9” front axle wheels and 8.25”/9” single mounted trailing axle wheels)

Figure 7

VH reference
11718941
11684201
11469307

Description
Wheel-end monitoring sensor with mounting bracket (WEM)
Compensation plate
Special wheel nuts

Quantity*
1
2
10

*Quantity suited for one wheel-end

Parts of retrofit kit VH11726375 (= kit without wheel-end monitoring sensor!)
(for 8.25”/9” front axle wheels and 8.25”/9” single mounted trailing axle wheels)
VH reference Description
Quantity*
11684201
Compensation plate
2
11469307
Special wheel nuts
10
*Quantity suited for one wheel-end

JOB QUALIFICATION:
The task has to be carried out by an experienced automotive technician.

SPECIAL TOOLS, EQUIPMENT OR SERVICES:
This job requires no special tools, equipment or services.

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PREPARATIONS:
 Park the vehicle with the front wheels in the straight-ahead position. Apply the parking brake.
Stop the engine. Switch off all systems and turn off the battery isolation switch on the
dashboard.
 Install a "DO NOT OPERATE" warning message on the steering wheel.
 Put chocks in front of and behind the front-axle wheels.
 Read the entire procedure before starting to work.

WARNING!
Observe safe shop practices at all times.

PROCEDURE:
Step
1

Action
If installed, turn two adjacent wheel-nut caps counterclockwise with a socket wrench until
they are free.

Figure 8: Wheel-nut cap

2
3

Remove the two adjacent wheel nuts.
Orientate the WEM on the wheel bolts as indicated in figure 9. Arrow points towards
tire!

Figure 9: Proper
orientation of WEM

4




For front axle wheels and single mounted trailing axle wheels: secure the
WEM with two special wheel nuts from the kit.
For drive axle wheels and dual mounted trailing axle wheels: secure the WEM
with the formerly removed wheel nuts.

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5

6
7

For 8.25”/9” front axle wheels and 8.25”/9” single mounted trailing axle wheels:
remove four adjacent wheel nuts and install one of the two compensation plates by
using four special wheel nuts from the kit.
For 8.25”/9” front axle wheels and 8.25”/9” single mounted trailing axle wheels:
repeat step 5 for the other compensation plate.
 For 8.25”/9” front axle wheels and 8.25”/9” single mounted trailing axle
wheels: tighten the wheel nuts evenly by alternately turning every nut
progressively further each time, until the torque of 600 ± 20 Nm (445 ± 15 ft.lbf) is
reached. Tightening sequence: refer to figure 10.

Figure 10



8

For 10.5” front axle wheels and 10.5” single mounted trailing axle wheels:
tighten the two wheel nuts to a torque of 600 ± 20 Nm (445 ± 15 ft.lbf) .
 For drive axle wheels and dual mounted trailing axle wheels: tighten the two
wheel nuts to a torque of 600 ± 20 Nm (445 ± 15 ft.lbf) .
Place the wheel-nut caps loosely on the wheel nut.

Figure 11

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9

CAUTION!
Use only a socket wrench to secure the wheel nut caps.
Using a socket wrench, turn the wheel nut caps approximately 15° clockwise until you
feel resistance.

Figure 12

10

NOTE: WEM comes in “transport” mode. It must be put into the “standstill” mode using
the magnet that comes with the WEM (mode switching is indicated by a LED lighting).
It automatically switches from “standstill” to “operating” mode according to vehicle
movement..
Change the WEM from “transport” to “standstill” mode.
Action
Put the magnet on the plastic housing
until the LED lights.
Put the magnet on the plastic housing
until the LED lights.

Result
LED lights green for 1 second.
The WEM is in “standstill” mode
LED lights red for 10 seconds.
The WEM is in “standstill” mode.

Figure 13: Use the magnet to change
mode of WEM

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RETIGHTENING WHEEL NUTS:
After mounting the WEM, retighten the wheel nuts after the first 50 km (30 miles) and again after
the next 100 km (60 miles). After that, check the torque daily until finally tight. Wheel nut
slackening is explained by the fact that in the beginning the fasteners set, so that part of the
original torque is lost.

DISCLAIMER:
The procedures contained herein are not exclusive. Van Hool cannot possibly know, evaluate, or
advise the transportation industry of all conceivable ways in which a procedure may be undertaken
or of the possible consequences of each such procedure. Other procedures may be as good, or
better, depending upon the particular circumstances involved. Each carrier who uses the
procedures herein must first satisfy itself thoroughly that neither the safety of its employees or
agents, nor the safety or usefulness of any products, will be jeopardized by any procedure
selected.

INFORMATION HANDLING:
Important supplements to and modifications of technical information not yet included
in the manual, are communicated by means of Service Bulletins
VAN HOOL CUSTOMER PORTAL:
Consult the customer portal regularly for the latest service documentation. Beside the maintenance
manual, you will also find the operating manual and the spare parts catalogue of your vehicle on
the customer portal. The customer portal is accessible through www.vanhool.be, and only with a
code (password) from Van Hool. If you do not have a password yet, request it by using the link on
the Van Hool website.

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