I put new leaf springs on my 06 silverado 1500 and and when I put the tires back on I noticed my rear passenger tire wobbles up and down by hand like a it would if a wheel bearing was bad I'm not sure how the rear wheel bearing works or of it's even a wheel bearing back there, I have drum brakes if that matters at all. How can you tell if it's the bearing?

 

Did you notice if it was wobbling before you changed the spring? If the wheel bearing was good before the change, it wouldn't be bad after changing a spring. Look for something else such as something being left loose.

 

I didn't try to wobble it before I did my springs but my wheel is tight.