Manitowoc MLC650, Service Maintenance Manual

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Reference
Only
Manitowoc
Published 09-09-16, Control # 229-09
5-83
MLC650 SERVICE/MAINTENANCE MANUAL HOISTS
5
55
• Clean the load block or the hook-and-weight ball.
• Lubricate the sheaves (if fittings provided), the hook
trunnion, the hook swivel, and any other part equipped
with a grease fitting at the intervals specified in the
Lubrication Guide.
• Tighten any loose tie-bolts, cap screws, and setscrews.
Check that all the cotter pins are installed with the legs
opened and trimmed.
• Check the sheaves for uneven wear in the grooves and
on the flanges. Check for loose or wobbly sheaves.
These conditions indicate faulty bearings or bushings.
• Check the fit of the wire rope in the groove of each
sheave.
- An oversized wire rope can crack the lip of the
sheave flange, causing rapid wear of the wire rope
and sheave.
- The groove must be larger than the wire rope, and
the groove must be free of rough edges and burrs.
• Make sure the hook, the trunnion, and the swivel rotate
freely without excessive play. Incorrect operation
indicates faulty bushings or bearings, or inadequate
lubrication.
• Check the swivel of the hook-and-weight ball for the
following conditions:
- Overloading—Spin the swivel by hand. If the motion
is rough or has a ratchet-like effect, the swivel
bearings are damaged.
- Side loading—This can cause the swivel to turn
freely in one spot and to lockup in another.
This condition can also be checked by checking the
gap (4c,
Figure 5-51 ) between the barrel and shank
(To check, the swivel must be removed from the
weight ball).
If the gap is wide on one side and closed on the
other side, damage is present.
NOTE: The gap between the barrel and the shank is
normally 0,5 mm (0.02 in) to 1,3 mm (0.05 in). If the
gap increases, swivel-bearing failure is indicated.
• Check the load block for signs of overloading:
- Spread side plates
- Elongated holes
- Bent or elongated tie-bolts
- Cracks
• Check all of the welds for defects and cracks.
• Check the wire rope for wear and broken wires at the
point where the wire rope enters the dead-end socket.
Check the socket for cracks. Tighten the wire-rope clips
located at the dead end of the wire rope.
• Make sure each hook has a latch and that the hook latch
operates properly.
Item Description
1 Socket and Wedge
2 Center Plates
3 Tie-Bolt
4 Sheaves
5 Sheave Shaft
6 Name Plate
7 Locking Cap
8 Hook Nut
9 Trunnion
10 Thrust Bearing
11 Latch
12 Hook
FIGURE 5-52
WARNING
Falling Load Hazard!
To prevent the load from dropping due to a hook or
shackle failure, do not attempt to repair any cracks in
hooks and shackles by welding.
Do not weld on any load-bearing component unless
proper welding methods are used (contact the Manitowoc
Crane Care Lattice Team for material and welding
specifications).