Gradall G-550C Operation And Maintenance Manual page 31

G-660C & G-880C GRADALL (Crawler)
A drive sprocket always has an uneven number of teeth. In this way the teeth and links always seek a
different notch, therefore giving more even wear.
If you notice that one side of the sprocket teeth are
wearing faster than the other, check the side frame for
uneven adjustment and check the track guides to
make sure that they are not worn excessively.
Wear measurements of the sprocket and the sprocket
rims is one of the most difficult to be evaluated. Under
normal working conditions, wear takes place in such a
way that no trace of the initial teeth is left, and you
cannot find any point to use as a valid reference. As an
approximate rule, replacement of the sprocket should
be made when the wear has reached the limits shown
in the sable shown below.
As the wear is never uniform, it is recommended that
measurements be taken on several teeth and where
the wear is the greatest.
MODEL NEW
G-660C 1.562" 1.609" 1.656" 1.703" 1.765"
G-880C 1.562" 1.593" 1.640" 1.687" 1.750"
WEAR AT SPROCKET TEETH
25% 50% 75%
As the chain links, bushings, and pins wear, there will
be a longer distance between bushings. This will
cause the bushings to move against the teeth on th
sprocket and cause wear. The experts claim that it is
difficult to do a good qualified job of building up worn
sprockets with weld. The uneven surfaces created will
cause accelerated wear to the chain bushings.
When the sprocket is worn out, do not replace the
entire assembly. If the hub is in good condition, cut off
the rim and weld on a replacement rim. Properly
arrached to the spokes of a good hub, the replacement
rim will give good service.
When replacing the rim, make sure re that the new one is
centered exactly.
100%
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OPERATION & MAINTENANCE