So I just got springs installed and the rears are uneven, one side sits about half inch higher than other side, is this difference normal/acceptable? Also, I hear knocking noises when my car bounces when I hit dips/bumps, is this normal?

 

when did you install the springs? what type of springs? are you looking at the height when your car is on level ground?

 

If the install was recent, you'd have to wait a few days or longer for the springs to settle. The height will eventually even out. However, depending on what kind of weight there is on the car and on which side of the car its on, there will be minor differences in height.

You'd have to go more in depth about the knocking noises. Not sure what kind of a noise that would be.

 

I installed the springs 8 hours ago, but the springs were used, Im not sure if settling applies to used springs. I measured it parked in my driveway which has a slight incline, Ill measure again on flat ground. I wonder if the install shop is to blame?

 

I'd imagine that the springs will still settle just a little. It'll take less time.

 

So I measured ride height on 4 different parking lots, the ride height varied from each parking lot, I guess its impossible to get dead even unless on perfectly leveled road. However the right side of the car is making rattling noise even driving in a straight line, is anyone else experiencing this with their springs?

 

The height between left and right should be off by mm not half an inch. The spring shouldn't settle but the rubber pieces will compress after a few days. You should see if all the nuts and bolts are on tight, torque it to the right spec. Springs it self should not make rattling noises unless you used the wrong springs. The aftermarket springs should be the same length as the oem springs, aftermarket springs compress more when weight is on it, that's how you get the shorter height. I just took out my coilovers and installed lowering springs last week.

 

The ends of the springs do not rest in the mounts in the same place as the OE springs. Depending on where the spring was placed (L/R) you might have some asymmetry that should go away with settling. That said, You really should not be hearing banning noises. Maybe something wasn't tighted properly. I would take it back to your shop just to have them give it the once over.