Manitowoc Grove RT765E-2 Service And Maintenance Manual page 188

HOIST AND COUNTERWEIGHT
• High external contaminations, such as dusty or sandy
conditions.
• Level of maintenance.
The following should be carried out following instructions in
Lubrication, page 9-1 and/or manufacturers instructions.
1. Pre-Use or Daily Inspection.
Must include but is not limited to the following inspections
that will be performed prior to placing the crane into service
and then as necessary during extended operation. This
inspection must be performed by a qualified crane operator
or qualified crane technician.
• Check for external oil leaks and repair as necessary.
This is extremely important due to the accelerated wear
that will result from insufficient lubricating oil in the hoist.
Hoists with a sight glass; check oil level daily. Hoists
without a sight glass; check oil level monthly if no
external oil leaks are detected. Lubricant level must be
maintained between the minimum and maximum levels;
midway up sight glass or at bottom of level plug port as
equipped. Use ONLY the recommended type of
lubricant. Refer to Lubrication, page 9-1.
• Check hydraulic fittings and hoses for chaffing,
deterioration or corrosion and repair as necessary.
• Visually inspect for corroded, loose or missing bolts, pins
or other fasteners and replace or tighten as necessary.
• Visually inspect rotation indicator transmitters, anti-two-
blocking switches and other safety equipment and repair
as necessary.
2. Quarterly Inspection (every three months).
Must include but is not limited to the following inspections
that must be performed by a qualified crane operator or
qualified crane technician.
• Perform the pre-use inspection.
• Inspect for corrosion of fasteners, hoist base, drum, etc.
and repair/replace as required to maintain the structural
integrity of the hoist.
• Check the hoist oil level. Inspect for any oil leaks from
the hoist gearbox.
3. Every 250 hours or 3 months.
• If applicable, lubricate the cable guide roller and cable
guard roller bearings.
4. Semi-Annual Inspections (every six months).
Must include but is not limited to the following inspections
that must be performed by a qualified crane operator or
qualified crane technician.
• Perform the Pre-Use and Quarterly inspections.
5-6
• Take a sample of the lubricant from the hoist gear cavity
as described in Gear Oil Sampling and Analysis, page 5-
7 and analyze it for wear metals content, correct
viscosity, lubricant deterioration, moisture and other
contaminants. If the oil sample contains a high amount
of metallic particles, the hoist must be taken out of
service to undergo a tear down inspection.
NOTE:
5. Annual Inspection.
This inspection must be carried out by a qualified crane
technician. The annual inspection MUST include, but not be
limited, to the following:
• Perform
inspection and Semi-Annual Inspection.
• Change the lubricating oil in the hoist gear cavity after an
oil sample has been taken as described in Gear Oil
Sampling and Analysis, page 5-7. Refill the hoist to the
proper level with recommended lubricant. Refer to
Lubrication, page 9-1.
Failure to use the proper type and viscosity of planetary
gear oil may contribute to intermittent brake clutch
slippage which could result in property damage, severe
personal injury or death. Some gear lubricants contain
large amounts of EP (extreme pressure) and anti-friction
additives which may contribute to brake clutch slippage or
damage to brake friction discs or seals. Oil viscosity with
regard to ambient temperature is also critical to reliable
brake clutch operation. Our tests indicate that excessively
heavy or thick gear oil may contribute to intermittent brake
clutch slippage. Make certain that the gear oil viscosity
used in your hoist is correct for your prevailing ambient
temperature.
• Check for correct function of the hoist brake by
conducting a high line pull load test, ensuring the brake
holds without creeping and that the hoist control is
correct. The function of the hoist brake should be
checked more often if abnormal operating conditions or
characteristics exist.
6. Every 10,000 hours or every ten years, it is
recommended that the hoist assembly be disassembled
and that all major components be examined for damage
and/or wear, i.e. gears, spline couplings, shafts, etc.
New components must be installed if any are found to be
worn or if there is evidence of heat or other damage. The
hoist should be reassembled using all new seals,
bearings, fasteners, washers, brake discs, brake
stators, sprag clutch, and springs. A comprehensive
Published 9-04-2014, Control # 422-08
RT765E-2 SERVICE MANUAL
Oil analysis alone cannot detect nor warn against a
fatigue failure.
the Pre-Use/Daily
WARNING
Inspection, Quarterly