BBSHD squeaking noise under load?

[krzychoniusz]

My BBSHD developed a loud squeaking noise when running at heavy load, very similar to what's shown on this video (see 30sec mark):

It's quite loud but only audible at heavy load, i.e. either when riding on throttle or pressing pedals hard (also without PAS). When I get off my bike and move pedals without any load it won't make that noise.

Any ideas what it might be?

Thank you

 

[soundwave]

try some lube on the motor gears

 

[krzychoniusz]

Just ordered molly grease, will be greasing it up next weekend

I suspect it may be something else though, as it started quite suddenly rather than building up over time. First squeaks heard after steep hill climb - could it be a worn out clutch? I did have an issue with grinding gears in winter at near zero temps and cold motor, but it seemed to go away as soon as weather got warmer or motor got hotter so I assumed thermal expansion of the nylon gear.