[madmaxx]

Yes mine were .75oz out of balance for the assemlby. This could mean the tire was out of balance 1.0 oz and the wheel 1.75oz and they complimented each other to reduce total out of balance to .75oz. I had some old GM shop manuals the real ones (Helm) and they always had a spec for rim imbalance, run out etc. The specs exist you just have to find the manual and then convince the manufacturer if GM feels they are necessary what is your justification why they are not.

I do not care if the rims were made on the moon, their mold may be bad, how they poured the mold was wrong, who knows, tell the idiot on the phone to let you talk to the qualilty control over the molding process.

I would instruct the shop to give you details of the imbalance on each wheel. If they are all out the exact same then it is a poor manufacturing process, if one is out more than the others, greater than 25% than it is defective.

There are no spots on the wheel to grind off to get it balanced so they have to add weights. I would have them mount the tires, road force balance and then dynamic balance and if they can get zero, take it for a ride and see if you get any vibration. You can balance a spinning stick but that does not make it round, I would be more concerend with rim runout, radially and axially, if the wheel is shaped like an egg and wobbles then you will always have vibration regardless of what the balance is.