Motor & Rotating Equipment Troubleshooting Guides

Motors, pumps, fans, and gearboxes wear out in predictable ways. A bearing that is about to fail will tick up its high-frequency vibration weeks in advance. A misaligned coupling will wear one side of a seal before it leaks. A loose foot will widen the resonance band in an FFT plot. The signal is almost always there if you look for it.

What you see first

Most rotating-equipment failures announce themselves. Your job is to catch them early enough to plan the repair.

Noise change: a new whine, rumble, or tick on a machine that used to be quiet.
Heat: a bearing housing that now burns your hand when you place it there.
Vibration rising on your monthly route: the FFT tells you which bearing and which stage.
Oil change showing metal: a flagging spectrographic count even without visible debris.
Seal weep that was not there last week, especially on the drive-end side.

Alignment is the one you keep getting wrong

Straightedge alignment leaves 5 to 10 times more residual misalignment than laser alignment does. That extra misalignment shows up as uneven seal wear, short bearing life, and 1 to 5 percent wasted power. If you do not have a laser tool, rent one for the day. The cost is less than one bearing replacement on a medium-sized pump.

Lubrication kills more bearings than anything else

Wrong grade, wrong amount, contamination, or a blocked breather that pressurizes the housing. Over-greasing is as bad as under-greasing. If you are not sure how much a bearing should get, find the OEM specification and log it on the lube route. Document the grease brand and grade. Mixing incompatible greases destroys them both.

When to hand it off

Call a reliability firm for vibration signatures you cannot read. Call the OEM for motor rewinds above 500 horsepower, for any turbine, and for the initial commissioning of a replacement machine. A bad start cuts asset life in half.

1 machines covered in this category

Baldor

Super-E (EM/EJMM)

NEMA Premium TEFC Industrial Motor

7 guides

Related learning

Deeper explainers and background reading for technicians working in rotating equipment.

Vibration Analysis Basics: What Your Equipment is Telling You

Every rotating machine vibrates. The pattern of that vibration tells you whether bearings are wearing, shafts are misaligned, or components are out of balance. Learning to read vibration data catches 90% of rotating equipment failures weeks before they happen.

Bearing Replacement: When, Why, and How to Do It Right

Bearings are the most commonly replaced component in industrial machinery. Yet 16% of premature bearing failures come from improper installation: wrong fit, contamination during mounting, or inadequate lubrication at startup. This guide covers the full process from selection to run-in.

Shaft Alignment Fundamentals: Precision That Prevents Failure

Misalignment is the second leading cause of rotating equipment failure after lubrication problems. Laser alignment takes 30 minutes and prevents months of accelerated wear on bearings, seals, and couplings. This guide covers the basics of angular and offset misalignment correction.

Lubrication Best Practices: The Most Overlooked Maintenance Task

Poor lubrication causes up to 40% of bearing failures. Wrong grease, wrong amount, wrong interval, or contaminated supply are the usual culprits. Getting lubrication right is the single highest-ROI maintenance improvement most plants can make.

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