Exmark StandOn 4500-620 - Manual (Page 15)

Maintenance
Lubricate Caster Wheel Hubs
Service Interval: Yearly
1. Stop engine, wait for all moving parts to stop, and
remove key. Engage parking brake.
Figure 13
1. Seal guard 2. Spacer nut with wrench
flats
2. Remove the caster wheel from the sulky frame.
3. Remove seal guards from the wheel hub.
4. Remove one of the spacer nuts from the axle
assembly in the caster wheel. Note that thread
locking adhesive has been applied to lock the
spacer nuts to the axle. Remove the axle (with
the other spacer nut still assembled to it) from
the wheel assembly.
5. Pry out seals, and inspect bearings for wear or
damage and replace if necessary.
6. Pack the bearings with a NGLI grade #1
multi-purpose grease.
7. Insert one bearing, one new seal into the wheel.
Note: Seals (Exmark PN 103-0063) must be
replaced.
8. If the axle assembly has had both spacer nuts
removed (or broken loose), apply a thread locking
adhesive to one spacer nut and thread onto the
axle with the wrench flats facing outward. Do
Not thread spacer nut all of the way onto the end
of the axle. Leave approximately 1/8 inch (3 mm)
from the outer surface of the spacer nut to the
end of the axle inside the nut.
9. Insert the assembled nut and axle into the wheel
on the side of the wheel with the new seal and
bearing.
10. With the open end of the wheel facing up, fill
the area inside the wheel around the axle full of
NGLI grade #1 multi-purpose grease.
11. Insert the second bearing and new seal into the
wheel.
12. Apply a thread locking adhesive to the second
spacer nut and thread onto the axle with the
wrench flats facing outward.
13. Torque the nut to 75-80 in-lb (8-9 N-m), loosen,
then re-torque to 20-25 in-lb (2-3 N-m). Make
sure axle does not extend beyond either nut.
14. Reinstall the seal guards over the wheel hub and
insert wheel into the sulky frame. Reinstall caster
bolt and tighten nut fully.
Important: To prevent seal and bearing damage,
check the bearing adjustment often. Spin the
caster tire. The tire should not spin freely
(more than 1 or 2 revolutions) or have any side
play. If the wheel spins freely, adjust torque on
spacer nut until there is a slight amount of drag.
Reapply thread locking adhesive.
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