Hello.

I've heard some humming sound at 0~20 mph and then it is getting louder when the car go faster. I doubt that the noise is from the bad rear hub assembly. I have some sockets from 5mm ~ 25mm but what size of nut does hold the hub? Here is the diagram.

 

I would guess 22mm

 

I think that's thread diameter, not socket size.

 

Yep. That is not the size of nut.

 

whoops. well i did find the part number for you: 90305-S30-003

maybe your local parts counter can tell you what size the nut is.

 

I'm sure OP has figured this out already, but for others looking for this info in the future, the socket size needed is 32mm for the rear spindle nut, and 36mm for the front spindle nut.