Shakes from 50mph and up

OK....I did this one to myself....sort of.....not all projects go as planned....

I bought new brake drums from Napa for $47 each.
Cleaned the oil off them, and spray painted them to keep them from rusting.....masking off the friction surfaces.
Put them on the car, rotated the tires at the same time. Tires were bought in November...so pretty new.

Went for a drive.....very smooth, braking very smooth......but....from 50mph and higher.....the car shook. Balance problem.

I rotated the tires back to the original positions. I rolled each tire with one hand on the tread to check for cupping.....watched the sidewalls for any sign of deformation as I rolled them. At the same time....I re-verified that none of the brakes were dragging....spinning each wheel when they were off the ground.... Car still shook.

Went to a tire place that I really trust...thinking I might have knocked a weight off .....had them spin ballance them....and rotate them. Car still shook from 50mph and up.

Took the new brake drums off....put the old ones back on.....they turned out to not be rusted as bad as I had thought.......
Went for a drive......problem solved.....NO shake......smooth

I would not jump at brake drums first for the symptoms I had......and Napa is known for quality. So.....following the steps that I listed is a good check process for the symptoms I listed.......but....I would not expect a brake drum to be out of balance. And I would have a hard time believing that I did it by spray painting them......

Golly! do you code? You're tolerance for tedium is well noted, and in my humble opinion, rare, and well suited to the task of coding software. Do you suppose that a weight fell off the drum before remanufacture?

That happen once on a Jeep I restored. But When I took the new ones off and put the old ones back on Yes it stoped,but I could not leave well enough alone, I put the news back on and it did not do it. I always adjust back brakes with the wheels and tires on so something may have happen then. not sure what but they worked great after.

I had adjusted the brakes.....as the diameter of the new drum would be smaller than the old.....had to adjust a bit to get them on.

I plan to take them back to Napa....and talk to them about it.

My father spoke to a mechanic back in my home town that I went to high school with.....and he said that he usually gets drums that sell for $100 and up each.....and still has problems with drums for all makes of cars. He also lightly turns new drums.....which I did not have done. So I may have Napa do that for me.

The fact that they are great below 50mph....and stop real smooth would indicate a ballance problem.....and it is certainly NOT the tires.....that seems to be the first place that we look.