I have an Onan 10K diesel generator in my motorhome. Model is 10HDCAA with about 4,800 hours on it.
About a year or so ago it developed a intermittent squeaking sound, like a fan belt slipping. I thought maybe the belts needed replace and since its under the back bed I had the Onan dealer replace the belts. When I got it back it was still doing it, the dealer said nothing wrong.

Since then it seems to be getting louder, but comes and goes at times. At times it will do it for long periods.

Small video you can hear it, not real loud at this time. Wife says she has a hard time sleeping its loud sometimes.
How concerned should I be? Seems to still work fine but if I can avoid more damage maybe should pull it out for a look?
Any ideas what this might be?


Short video:
https://youtu.be/2m2hoHGA1_8

Possibly and probably the bearing at the left side generator end.

One bearing supports the rotor and sits in an endplate.

Use something like a long piece of threaded rod.
Hold it on your ear with your thumb between the rod and your ear. Hold the other end various place on the generator barrel moving from the engine end on the right to as far back on the left end as possible.

You may be able to better pinpoint the noise...

I've replaced entire generator ends a number of times and worked on other racers machines that had similar noises and had gen ends replaced.....

Onan probably sells a replacement bearing.....I have replaced bearings on smaller machines that they do not sell the bearing. I was able to source one by size and change it...

On a 10 or 12 it's a big job.....Remove the machine and pull it apart...

Many older machines (2004-2005) if the rotor/stator fails Onan has no replacement available....Been down this road at least twice in the last year or 2...Waited months and eventually was told NOT available...

Thanks, Good tips.

Hopefully we can get through a couple more hot weekends. I can then make this a winter project.

September usually doesn't see many weekends we need the AC.