Can You Spot the Problem?

A few months ago, while teaching a shaft alignment training class, a customer asked if we could take a look at a machine that the maintenance group was having trouble assembling.

Backward HubAfter a quick inspection, the photo on the right was taken. Do you notice anything unusual? Leave a comment below if you spot it.

Don’t laugh! If you’ve been in maintenance for very long, you’ve probably done the same thing–or worse!

Sometimes, when performing troubleshooting as a part of shaft alignment, we miss some obvious clues. Things such as:

  • Shims stacks that are loose. A good sign of soft foot, a loose bolt or both.
  • Obvious coupling wear, such as that pile of bright orange dust underneath a bright orange coupling. There is really no good reason to align a worn coupling insert–replace it first.
  • Loose coupling hubs. Look for loose bolts, missing keys or an undercut shaft diameter.
  • Loose bolts in the baseplate or frame. This can be a cause of vibration, alignment discrepancies, wear, etc.
  • Pipe hangers, saddles, or stiff legs that aren’t supporting the weight of the piping.
  • Too much, or too little lubrication.
  • And yes, assembly errors.

VibrAlign sells some excellent alignment tools, but the two best alignment tools are your eyes and your brain. And the one quality that separates a mediocre “aligner” from an excellent “aligner” is the ability to troubleshoot.

Don’t forget the obvious.

About the Author

Stan Riddle

Stan Riddle joined VibrAlign in 2008. He has 30 years experience in aligning industrial machinery. Stan began his maintenance career working as a machinist and millwright for companies such as Weyerhaeuser, R.J. Reynolds, and Tyco Electronics. He also has over 25 years experience in Predictive Technologies, such as vibration analysis, thermography, oil analysis, and ultrasonic inspection.


He is a certified Level III Vibration Analyst with the Vibration Institute, and is a Past Chairman and Board Member of the Piedmont Chapter.


Stan and his wife live in Yadkinville, NC where he enjoys wood carving, fishing, and anything else outdoors.


7 Comments
  1. The guy put the Flange on the reverse with the hub towards the counter flange ….

  2. This is the kind of “gotcha” that happens to everyone eventually.

    Just because the pieces seem to fit together doesn’t mean they’re assembled correctly!

    • You’re right Alan! There’s nothing quite so disappointing as completing an alignment, only to look over and see you forgot to put the retaining ring on! I admit, I’m guilty!

  3. jimmie rodrigue

    Coupling installed incorrectly

  4. jgentleman

    Just testing this to see what happens.

    • Hey, Joel. Since it’s moderated, I get a notification of your reply and then approve it. Cuts down on spam.

      Did you spot what was wrong?

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