Maintenance
139
Checking and tensioning the crawler tension
When parking an excavator with rubber crawlers, ensure that the
seam ( ) is on top half way between the two sliders (see figure/1,
"Checking the crawler tension", page 139).
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Clean all parts of the running gear, paying particular attention
to stones between the crawler and sprocket or idler. Clean the
area of the crawler tensioning cylinder.
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Swivel the swivel frame 90° to the direction of travel as shown
in the figure.
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Lower the front attachments on the ground and raise the exca-
vator about 200 mm off the ground on one side.
Checking the crawler tension
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The crawler seam (1) is half way between the idler and sprock-
et.
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Check the crawler sag as shown in the figure.
Crawler sag "A"
10-15 mm
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If the crawler sag is more than 25 mm, adjust the crawler.
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If necessary, tighten or loosen the crawler.
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Start the engine and rotate the lifted crawler briefly.
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Recheck the crawler tension, readjusting it if necessary.
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Perform the procedures on the second crawler.
If the crawlers are too tight, wear is increased.
If the crawlers are too loose, wear is increased and the crawlers may come off.
Have a guide supervise the procedure.
Support the excavator with appropriate backing material, observing the vehicle weight.
Caution: The area around the rotating crawler must be free of persons. Turn the starter switch to the
STOP position after turning and remove the key.
∞
STOP
STOP
