https://honda-tech.com/zerothread?id=86477

I found out what it is, and figure I should share the info. All these shops that said "no, problem with your brakes" and cleaned it, NEVER really clean it. I took the rear drum brake cover open and found lots of brake dust.

That "sound" was the result of drum brake cover rubbing on the brake housing as it spin because there was brake dust in-between. So there was friction. As it spin, it gathers up together into almost a lump. So each time the cover rolls over the lump, it make the metal sound.

And what else?

These shop use an impact wrench and tighten the bolts uneven. This cause the cover to be tighter one side vs the other. Therefore, the break dust builds up (gathers up) to form a lump as it spins.

In conclustion, DO NOT let shops use an impact wrench on your wheel. I thought they know better since they do tires/wheels too. But they don't give a rat's *** about the care of your car.

It's zipppp, ziiipppp, ziiipppp, zipppp. Done

After I cleaned it myself, tighten it myself. The noise is GONE!!!!!!!!

It's been 2 weeks since.