ASV ST50 Scout, Operation And Maintenance Manual

Page: 47 / 60

MAINTENANCE
Drive Sprocket Rollers
46
Drive Sprocket Rollers
ASV undercarriages utilize
rollers on the drive sprockets to
drive the track. These rollers
help minimize friction between
the track and the drive sprocket
to prolong track life. The rollers
rotate around hardened steel
pins and usually wear on their
inside surfaces.
As they wear, the rollers become
thinner, but will continue to func-
tion as long as they rotate freely
around the pins.
Sprocket rollers should be
inspected every 50 hours of
operation and replaced if
cracked or worn to less than
35% of original thickness. (.088”)
Roller Replacement
Turn the engine off, remove the
key from the ignition and discon-
nect battery prior to performing
this procedure.
To replace worn rollers:
1. With the machine turned off
and parked in a safe working
area, remove the track to
expose the sprocket for roller
replacement. (see page 40)
2. Remove one bolt (A) holding
washer (B), steel pin (C),
roller (D), and external roller
(E) in place. The pin and
roller may then be removed
from the sprocket. (fig. 19)
3. Install a new roller over the
pin.
4. Slide the bolt back through
the sprocket, washer, pin, and
external roller. (fig. 19)
5. Install and tighten the retain-
ing nut (F).
6. Repeat this procedure as
required throughout the
sprocket.
7. Reinstall the track. (pg. 43)
8. Repeat this procedure on the
other side of the machine if
necessary.
9. Perform the track tension
adjustment procedure. Roller
replacement is now complete.
Note: ASV recommends replac-
ing external rollers as a set to
simplify inspection and maintain
proper sprocket function.
Note: Internal pins should be
inspected when replacing rollers.
Internal pins do not rotate during
operation and may experience
uneven wear. Replace if worn to
less than 35% of original thick-
ness.
19
Steel Pin
New Roller 35% worn
.088”