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7 - 2
Section 3
Routine Maintenance
9803/6020
Section 3
7 - 2
Issue 1
Tracks and Running Gear
(continued)
Checking/Adjusting the Track Tension
1
Prepare the Machine
a
Position the machine on firm and level ground.
!
WARNING
NEVER position yourself or any part of your body
under a raised machine which is not properly
supported. If the machine moves unexpectedly you
could become trapped and suffer serious injury or be
killed.
INT-3-3-7
b
Raise the track to be measured off the ground
(see
Cleaning the Tracks
, steps 1 and 2). Block
the undercarriage.
c
Rotate the track in forward direction only to
ensure that the track is able to rotate freely.
d
Stop the engine and remove the starter key.
2
Check the Tension
Measure dimension
A
(see table below), between
track plate and undercarriage, at the third roller
counting from the idler wheel end.
Note:
In certain ground conditions, e.g. soft sand and
sticky mud, the chain tension may increase as the machine
is operated and material is packed between the chain and
sprocket/idler wheel. In this case, the tension should be
checked again after approximately 5 minutes tracking.
Dimension
A
(mm)
Hard Ground
(Metal Plates)
180 - 205
(Rubber Plates) 125 - 135
Soft Sand/Sticky Mud
250 - 275
3
Adjust the Track Tension
!
WARNING
When opening the check valve always stand to one
side and loosen a little at a time until grease starts to
come out. It you over-loosen too much grease could
spurt out or the valve cover fly out and cause serious
injury.
8-3-4-5
!
WARNING
Under no circumstances must the check valve be
dismantled or any attempt made to remove the grease
nipple from the check valve.
8-3-4-9
A
C
B
a
If the track is too tight, release a small amount of
grease from the tension unit, by loosening the
check valve
B
on the tensioner.
Note:
A maximum of 3 turns of the check valve should be
sufficient.
b
If the track is too slack, pump grease into the
tensioner.
Note:
If dimension
C
is (or becomes) zero before (or
during) tensioning, this indicates that the track and/or its
associated components require attention. Continued use
could cause further serious damage.
4
Lower the Track
Remove the blocks from beneath the undercarriage
and lower the track to the ground using the boom and
dipper controls.
5
Repeat for the Opposite Track
Swing the boom round to the other side and repeat
steps 1 to 4.
Note:
The machine shown is typical. The track rollers must
be counted from the front, i.e. the idler end. The example
shows the measurement taken at track roller number three.
Summary of Contents for JS70
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