I recently replaced my brake drums with new ACDelco drums. I think I noticed an increased vibration in the rear after this. I had the rear wheels checked for balace, but they were OK. The tire-guy suggested to try to measure the drums on the wheel balancing machine, and said yes.l After spinning the drums on the machine the machine reported 30 + 40 grams unbalance.

1. Can one check drum balance this way?
2. Any chance I got wrong type of drums?

 

Never have I ever heard an issue with drums being out of balance...

Have him 'balance' your old drum and see how it comes out.

 

Did he put the drum on the wheel balancer when he did this test..

 

Just take em back to the store (auto zone?) And tell em their ****ed up and get a new set. If it still does it, then its probably not the drums.

 

Oh and I assume u did the rest of the rear brakes too? Could also be an issue if you have worm shoes on a new drum...

 

The only thing close would be to have them turned on a lathe. But it is not called balancing. When I install new drums or rotors I do have them turned because it will make them more true.

 

Yes

 

No. A tire balancing machine is designed to balance tire and wheel combinations of a known circumference and width. Swap wheels side to side just for fun and see what happens.