Manitowoc Grove RT770E, Service Maintenance Manual

Page: 207 / 357

5-7
RT770E HOIST AND COUNTERWEIGHT
5
Published 11/26/2014, Control # 447-05
GROVE
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.
• 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: Oil analysis alone cannot detect nor warn against a
fatigue failure.
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 the Pre-Use/Daily Inspection, Quarterly
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
Lubricants and Lubrication Intervals , page 9-1.
• 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
hoist line pull and load holding test must be conducted
following the repair work.
Oil Sampling
Oil Change
The hoist gear oil must be changed after the first 100
operating hours then on an annual basis, at a minimum
thereafter. In severe duty applications, the gear oil should be
changed every six months. Use the recommended
lubricants. Refer to
Lubricants and Lubrication Intervals ,
page 9-1.
Gear Oil Sampling and Analysis
Proper gear oil sampling and analysis is a vital part of a
comprehensive preventive maintenance program.
Information obtained from the oil analysis allows the
m a i n t e n a n c e t e c h n i c i a n t o s u b s t i t u t e p r e v e n t i v e
maintenance for more costly unscheduled down time or a far
more dangerous failure. Early detection of accelerated
component wear allows the scheduling of corrective
maintenance.
WARNING
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.