Crane and hoist gear case inspection

Why would my crane need a gear case inspection?

Many cranes have been in service for 20 years or more. This is especially true for very large cranes such as those used in heavy industrial environments. The basic technology of crane design has advanced in many areas including motors, controls, human interface and wire rope design, among others.



One area of particular concern is hoisting gears. In general, the gear cases used in cranes have proven themselves to be reliable workhorses capable of delivering years of service with minimal maintenance; however, in many applications, “thin rim gears” that do not meet today’s gear design standard are prevalent.

These gears have an insufficient tooth depth-to-rim thickness ratio that is inherently more conducive to fatigue failure. In addition, production may have significantly increased over the years. This increase in usage makes the cumulative effects of fatigue much more important in these typically intermittent use devices.

While cranes are routinely given thorough inspections, the internal gear case components are not periodically evaluated by skilled personnel trained to recognize potential gear system problems.


Gear Case Inspection

The Gear Case Inspection assesses the internal gear case components that are not typically evaluated during routine inspections. It has been designed to uncover issues that may lead to hoist gear failure.

Inspections are performed by trained service personnel who will:

  • Review your maintenance and inspection history
  • Perform a visual inspection of the gear wheels, bearings, shafts and keys using an endoscope
  • Visually inspect the gear case and its mountings
  • Perform an oil analysis and check the oil level


Advanced Gear Case Inspection

During this inspection, your gear case will be disassembled for a comprehensive assessment of the internal components that are not typically evaluated during a routine inspection. While the gear case is disassembled, the gears, keys and shafts undergo a full examination that may include non-destructive testing techniques such as dye-penetrant and magnetic rubber.

Because your gear case is already disassembled, bearings, seals and lubricants are typically replaced. It is also highly recommended that critical spare parts are ordered prior to the inspection and are on hand in the event that they need to be replaced to limit equipment downtime.