Excess load may well be manifested in other parts of the envelope spectra besides 0x, 1x and 2x but short term trending of these frequencies can give you real insight as to what is causing the high loads, assuming that you think through the process. For a list of symptoms )0x is number 12 and includes the inability of the lubricant to support the applied loads), see table 1 in:

http://vibrotek.com/article.php?article=articles/new94vi/index.htm

Had seen something similar sometime (longtime) back. The grease in that motor too had hardened and was not allowing the cage to rotate. BUT the balls did rotate along with the inner race creating those wear marks only on the outer and inner sides.
That could also explain why the races have peculiar wear markks.
Did you get some rain sometime. The cage looks corroded too...

Thanks for the comments.

If the cage was stationary, there would have to be substantial sliding or skidding between the balls and one of the two races (can't roll on both races at the same time if cage is stationary). I would think that might give a much less uniform pattern than what we see here. For one thing, I would expect a change in pattern on the outer race associated with balls coming in and out of the load zone (affects skidding tendency).

But what I see is a uniform pattern all the way around the inner ring and outer ring. I attribute that to a rolling ball track which is more exagerrated than normal due to poor lubrication and/or loss of intertnal clearance due to heating which increases the loading.

That's just my opinion, but I could be wrong..always open to comments.

But now that you mention it:

The 2nd machine with the same symptoms (FTF sidebands around BSF harmonics where BSF harmonics were very low) had the symtpoms with very high magnitude at the inboard bearing. Disassembly of the inboard bearing showed similar poor lubrication conditions.

However on the outboard bearing, we noticed that when we held the bearing in our hand, we could rotate the inner ring without rotating the cage (see attached video). I attributed it to the grease being cool and no load on the bearing. But interesting that you have brought this up. Since we have two different sizes of bearings on inboard and outboard, I will go back and double-check whether that frequencies matched the inboard or outhboard. Note that races on the outboard bearing of this 2nd machine didn't show a heavy track. If I get a chance I'll post all the info for this 2nd machine.

This message has been edited. Last edited by: electricpete,

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