HOISTS 777 SERVICE MANUAL
5-22 Published 10-01-2012, Control # 045-08
Sheave, Roller, And Drum Inspection
Perform the following inspections WEEKLY.
1. Check drum clutches and brakes for proper adjustment.
2. Check sheaves, rollers, and drums for following
conditions:
a. Unusual noises.
b. Freedom of movement -- must turn freely by hand.
Wire rope may have to be loosened to perform this
inspection.
c. Wobble -- must turn true with very little side-to-side
or up-and-down play.
d. Signs of rust (indicating that water may have
entered bearing).
e. Grease leaks (indicating a faulty seal or water in
grease).
Above problems indicate bearing damage. If found,
sheave, roller, or drum should be disassembled for
further inspection. New bearings should be installed.
For sheaves not equipped with grease fittings, be sure to
pack new bearings with grease at assembly.
3. For steel sheaves, check depth, width, and contour of
each sheave using a groove gauge as shown in
Figure 5-18. Replace sheaves that have over or under
size grooves.
4. Replace grooved drums that allow one wrap of wire rope
to contact next wrap as rope spools onto drum.
5. Inspect sheaves to verify they do not contact another
sheave or structural plate work. There should be uniform
clearance between sheaves in a cluster. Repair or
replace worn or damaged sheaves.
6. Re-machine or replace steel sheaves, drums, or rollers
that have been corrugated by the wire rope’s print as
shown in Figure 5-19.
NOTE: Depending on the type of wire rope used, It is
normal for nylon sheaves to show the wire rope
print. Do not re-machine nylon sheaves.
7. Inspect nylon sheaves for excessive measured for
excessive tread diameter wear at locations E in
Figure 5-21. Measure at three positions to check for
uneven wear.
Wear must not exceed limits given in table. Replace
worn or damaged sheave.
NOTE: Nylon sheaves cannot be accurately inspected
using conventional methods such as sheave
gauges.
Due to the characteristics of nylon sheaves, the
nylon material will actually move to better support
the wire rope as the sheave wears normally.
Nylon sheave properties will be degraded in
temperatures above 140° F.
FIGURE 5-18
A925
135°–150°
Observe groove to see if contour of gauge
matches contour at bottom of sheave groove.
Proper fitting sheave groove should support
wire rope or 135–150° of rope circumference.
Groove Too Small
Groove Too Large
WRONG
RIGHT
FIGURE 5-19
S150
“Corrugated” steel sheave,
roller, or drum will cause
wire rope to wear rapidly.
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