Performing visual inspections, checking for signs of wear or fatigue, and cleaning couplings regularly.
Checking and changing lubricant regularly if the coupling is lubricated. This maintenance is required annually for most couplings and more frequently for couplings in adverse environments or in demanding operating conditions.
Documenting the maintenance performed on each coupling, along with the date.

Even with proper maintenance, however, couplings can fail. Underlying reasons for failure, other than maintenance, include:

Improper installation
Poor coupling selection
Operation beyond design capabilities.

The only way to improve coupling life is to understand what caused the failure and to correct it prior to installing a new coupling. Some external signs that indicate potential coupling failure include:

Abnormal noise, such as screeching, squealing or chattering
Excessive vibration or wobble
Failed seals indicated by lubricant leakage or contamination.

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