My rear left wheel is making a terrible squealing and squeaking noise over every bump in the road, as well on slanted non flat roads. It will just *Squeak squeak squeak* down the whole road.

I haven't tried anything yet, but im diagnosing it as bad shocks. Or bad wheel balance.

Any other things could cause this?

 

Start by checking your brakes also look for a rock being stuck between the rotor and dust shield. From there check to make sure the tire isn't rubbing the wheel housing or something near that. If so now you have to figure why it is rubbing. Check all the rear axle links and shock bushings. Usually when the shocks are bad they will be leaking fluid so if it has lost all of it's fluid the seals inside of it could be making noise.

Jeff

 

Could be as simple as worn brake pads, causing the wear detection finger on the pad backer to rub on the rotor and make the "squealing" noise to alert you to the fact your pads are worn out.