Jaypro Sports MHWM-D-A - Manual (Page 13)

© 2005 Jaypro Sports Equipment JSL-Inst001 Rev G 10-24-2006 13 of 40
b. Do not substitute with pulley or block & tackle assemblies that are not rated for adequate load.
c. A minimum of 1.6 Ton working load at a 5:1 safety rating is required.
d. Any cracks or deformation in any of the components of the pulley or shackles are cause for
replacement.
e. Inspection criteria (Source: The Crosby Group, Inc., P.O. Box 3128, Tulsa OK 74101, 918-
834-4611):
i. Wear on pins or axles, rope grooves, side plates, bushing or bearings, and fittings.
Excessive wear is cause to remove from service and replacement.
ii. Deformation in side plates, pins and axles, fitting attachment points, trunnions, etc.
Deformation can be caused by abusive service and or overload and is cause for
removal from service and replacement.
iii. Misalignment or wobble in sheaves.
iv. Security of nuts, bolts, and other locking methods, especially after reassembly
following a tear down inspection. Original securing methods should be used; e.g.,
staking, set screw, cotter pin, cap screw.
v. Pins retained by snap rings should be checked for missing or loose rings.
vi. Sheave pin nuts should be checked for proper positioning. Pins for tapered roller
bearing should be tightened to remove all end play during sheave rotations. Pins for
bronze bushings and straight roller bearings should have a running clearance of .031
inch per sheave of end play and should be adjusted accordingly.
vii. Hook or shackle to swivel case clearance is set at .031 to .062 at the factory. Increased
clearance can result from component wear. Clearance exceeding .12 to .18 should
necessitate disassembly and further inspection.
viii. Deformation or corrosion of hook and nut threads is cause for removal from service
and replacement.
ix. Welded side plates for weld corrosion or weld cracking.
f. Regular maintenance – apply lubrication to the following according to schedule:
i. Tapered roller bearings – Every 30 days of intermittent operation.
ii. Roller bearings – Every 14 days of intermittent operation.
iii. Bronze bearings (not self lubricated) – Every 14 days of intermittent operation.
iv. Bronze thrust bushing or no bearing – Every 21 days for infrequent swiveling.
5. Wire Rope
a. Wire rope should be lubricated regularly to insure long reliable life. Obtain a suitable wire rope
lubricant from local supply or hardware store. Do not use heavy grease or engine oil for
lubricant. A recommended penetrating lubricant is MIL-G-18458 wire rope grease. Lubrication
is best applied at the point of the wire rope bending over the pulley sheave, where the strands
will be temporarily and partially separated allowing the lubricant to penetrate fully.
b. Inspect rope for excessive damage or broken ‘threads’. See image below – if wire rope looks
like either of these pictures, it’s time to replace it: