Balancing rear brake drums

[BobW]

I can report that balancing the drums was a good thing to do, in my case. Vibration gone.

[jbcollier]

Good question Jerry.  I have seen drums without the lip.  I would be concerned if they were front brake drums as uneven heat loading could cause cracking.  Not really with the rear brakes though as they don't really do much compared to the fronts.