6.14.2 Drive belt – Tension check
Preconditions
☑ Engine is stopped and starting disabled.
Special tools, Material, Spare parts
Designation / Use
Part No.
Qty.
Tester
Y4345711
1
Belt tension tester, 150-600 N
Y20097429
1
Fan drive – Checking belt tension
1.
Remove protective cover.
2.
Set belt tension tester onto the drive belt in
the middle between the belt pulleys (arrow).
3.
Using pushbutton, press vertically on top
side of drive belt exerting even pressure un‐
til spring engages noticeably.
4.
Do not press any further, otherwise the dis‐
play value will be falsified.
5.
Take off tension tester without changing the
position of the display arm.
6.
Read off measured value at the intersection
of display arm and "KG" scale. For specifi‐
cations, refer to table below.
Application
Specification
Initial installation (new belt)
Specification
Operating tension (used belt)
Fan drive belt
Frequency: 99 ±1 Hz
Frequency: 86 ±1 Hz
Table 2: Measuring belt tension with frequency meter
Application
Specification
Initial installation (new belt, run‐
time 0.5-2 h)
Specification
(used belt, runtime 500 h)
Fan drive belt
Depression depth: 5.6 mm
Test force: 188 N
Depression depth: 7.2 mm
Test force: 188 N
Table 3: Measuring depression depth with tension tester
Application
Specification
Initial installation (new belt, run‐
time 0.5-2 h)
Specification
(used belt, runtime 500 h)
Fan drive belt
Static tension: 4000 N
Static tension: 3000 N
Table 4: Measuring static belt tension
7.
If the measured values deviate from the specifications above, adjust drive belt tension (→ Page 96).
8.
Install protective cover.
MS150094/01E 2012-08 | Task Description | 95
TIM-ID: 0000025518 - 002
