This is not the first time I clean it, cleaned it many times before and not issues, for this issue I checked everything in the back and the motor pulley looks good and working when I push , but whenever it starts preheating this sound starts, I tried roasting, the sound is still there and only stop if I disconnect the bullet from electricity.
I believe something with the rings “washer?” I don’t know the names but they are the only things that I have no clue how to assemble but just put the two thin ones first then then the thicker one last and it rolls and rolling normally as seen in the video,
These bearings are dirt cheap on amazon - every skateboard in the world uses this size bearing.
I’d just replace the bearing. If possible I’d choose a sealed bearing (just avoid rubber seals), which will not (and cannot) require re-lubricating. Or a double shielded bearing, which can be relubed, but has shields which help prevent the bearing from getting dirty.
Other than the heat, this is not a challenging situation for the bearings. If you decide to relube, you might go for a heavy, high temp, food grade silicone grease.