Metallic spinning sound coming from rear

[Jand3rson]

My wife's E30 is making a metallic kind of "spinning" sound at the rear of the car. It starts at about 20 mph, and gets faster with speed, and goes away when you slow down. The brakes in the rear look fine, any ideas?

[Erick]

It's not the best description I've heard in my life, but I'll throw in 2 cents on the rear wheel bearings.

[kylebes1]

diff fluid ok>?

[Jand3rson]

It's not the best description I've heard in my life, but I'll throw in 2 cents on the rear wheel bearings.

Yeah, I can't really think of a better way to describe it.

diff fluid ok>?

I have not checked it. How do you check the fluid?

[kylebes1]

there are two plugs on the rear cover, on above the other. it takes a large allen wrech type socket, cannot remember size or anything. remove the top one to check the level by inserting your finger. you should fell fluid just below the plug opening. if you cannot feel any go ahead adn drain the fluid through the lower plug and refill it after reinstalling the lower plug.