Section 4: Maintenance & Lubrication
OFM3678, OFM3690 & OFM3698 Offset Flail Mowers 333-149M
6/11/21
47
Check Belt Tension
WARNING
!
To prevent serious injury or death:
Always shut tractor down using “Tractor Shutdown
Procedure” provided in this manual before servicing,
adjusting, cleaning, or maintaining this implement.
Check belt tension after the first few hours of use and,
subsequently, every 30 hours, or when necessary.
Excessive or inadequate tension will significantly reduce
the lifespan of the belts.
To maintain uniform belt tension, the belts must always
be replaced together as a set and never individually.
To check the belt tension correctly:
•
Remove fastener bolts, associated washers, and
transmission cover over the belts,
•
A number of methods are possible for checking belt
tension.
Two possible methods are described as follows:
A)
Use the instrument provided by the belt manufacturer.
B)
Use a belt frequency meter.
Instrument Provided by the Belt Manufacturer
Figure 4-1
Belt Manufacture Instrument
Refer to Figure 4-1:
The diameter of the smallest pulley and the
characteristics of the belt must be known to use this
method.
1. Make sure the belts are completely stationary.
2. Place the instrument against the mid-point of one of
the belts.
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3
2
4
76019
3. Push button (#1) slowly down and firmly with your
finger.
4. Stop pressing as soon as you hear a click, and
remove the instrument.
5. Read the value on the graduated scale (#4) at the
exact point where the top of indicator arm (#3)
crosses the scale (#4).
6. Refer to the tension table provided with the
instrument to determine the tension. In general,
correct tension values are approximately:
•
90 ft-lb (600 N) after initial installation
•
100 ft-lb (460 N) after running-in
Belt Frequency Meter
Figure 4-2
Belt Frequency Meter
Refer to Figure 4-2:
1. Make sure the belts are completely stationary.
2. Hold the frequency meter (#1) near the belts and, if
possible, hold the meter against a fixed surface to
prevent your hand from moving and producing an
incorrect reading.
3. Touch the belt to make it vibrate.
4. Read the belt response frequency on the display.
5. The correct frequency is approximately:
•
86 Hz after initial installation
•
72 Hz after running-in
IMPORTANT:
The indicator arm (#3) must be
pushed down into the body of the instrument.
IMPORTANT:
Do not touch the indicator arm during
this procedure as this will produce an incorrect
reading.
IMPORTANT:
Measure the tension of all the belts if
possible and calculate the average value.
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76020
IMPORTANT:
Measure the tension of all the belts if
possible and calculate the average value.
