On Friday, January 18, 2019 at 6:34:36 AM UTC-8, StarDust wrote:
https://www.youtube.com/watch?v=EE0FK0KDROw

I think, I can used this belt drive?
My Vixen GP/D EQ gears gets very noisy too in the silence at night!

It looks like that middle gear may be too loose on the fixed shaft and is wobbling. You could try removing the gear and putting a thin layer of heavy grease on the shaft before reinstalling the gear.

All three gears could stand a thin layer of grease on the teeth to cut down on friction wear.