JLG X23J Operator Manual - Manual (Page 141)

137
BOOM LIFT MODELS X23J
JLG
X23JR0620113
‑ functioning on sandy land.
C) Separation of the metal cores
The metal core acts as a type of adhesive of the rubber between the core itself and the steel
ropes. Separation may be caused by
excessive tension as breakage of the ropes for the following
reasons:
‑ the metal cores have been wound by the worn toothed wheel as
indicated in the figure. When this wear and abrasion is
detected, the toothed wheel must be replaced as soon as possible.
If it breaks, as stated in paragraphs A‑B‑C the track must be
replaced because this damage leads to a complete loss of func‑
tions.
D) Abrasion and fatigue cracks
1. The cracks at the base of the carved profile occur due to bending fatigue of the rubber cau‑
sed by the toothed wheel and the track‑tensioning wheel.
2. The cracks and bends on the edge of the rubber are due to
manoeuvres with the track in presence of cement kerbs and
edges.
3. The cracks and abrasions in the rubber on the tracks of the roller guide originate from fati‑
gue from the compression of the rubber by the weight of the wheel, together with functio‑
ning on sandy land, or repeated and abrupt changes of direction.
4. Abrasion of the carved profiles may occur especially if slewing on concrete surfaces or on
gravel or hard surfaces are carried out.
The damage indicated in paragraph D points 1.2.3 must not be considered fatal for the track
and, even if in presence of gradual and progressive damage, they allow the track to continue
working.
The development of the damage indicated in point 3 leads to the exposure of the metal cores
and if they are exposed for more than half of the track circumference, it means that it is time
to replace them. It can however still be used.
E) Cracks due to external factors
Cracks on external track surfaces (those in contact with the ground) are often due to contact
with gravel, sharp stones, sharp materials, nails, glass, which cause cuts. From the rubber pro‑
perties point of view, this is inevitable although it does depend on service conditions.
Cracks on the internal surface of the circumference and on the edge of the rubber originate
from contact of the belt with the structure of the undercarriage or with sharp concrete edges.
The increase in cracks is relatively small.
Even if it does not appear to be in good condition the track can be used in heavy duty condi‑
tions.
PARTI USURATE
CRACK
W
ORN PARTS