This has turned in to a full blown problem:
https://www.gmforum.com/general-gm-c...needed-305249/

So, after cursing ACDelco for their out of round/balance drums I received from RockAuto, I decided to pick up a pair of drums from O'Reillys to end the agony. I swapped the drums, only to find I have the exact same issue.

Here is some more information:
With the LR up in the air, you can spin the wheel. It will go from no contact with the brakes, to the brakes dragging enough that you have to put some effort in to turning the wheel. It then eases back up to a free spin, until you hit the same spot again where the brakes start to drag. I swapped to the new unit on the left side, and it is EXACTLY the same. I then moved to the right side, and jacked the right rear. Spinning the wheel on this side, it goes from no brake contact, to detectable contact, back to no contact with each rotation. If you were to just spin the wheel, it would likely make it 3 or 4 rotations until it drug to a stop, as opposed to the left which will usually stop dead.

I moved the drum that was on the left, to the right side, and the right side has the exact same feel, no matter which drum is on it of the 3.

I can't figure out what is going on with this. I haven't driven the car with the new drums yet, but I expect that it will be exactly the same. What would cause this. The only thing left back there that spins is the hubs, which I have to assume are factory originals. There is no detectable play anywhere, but as was mentioned, I suspect the previous owner drove with the parking brake on and cooked everything. The only thing that comes to mind is that the hub is warped.

What else could it be. With hubs at $100 or so (with RockAuto closeouts being the exceptions), this is above the "throw parts at it until something sticks" threshold.

is eveything well in place behind the drum springs pads etc.., id check that before anything

I have the same issue

Have been putting on Wear-Ever drums from advance autoparts, and drive them for a few weeks, and return them, trade for new ones

out of the box, they do not seem to be round, when installing, they are scraping as if they are out of round. I ask the auto parts place to check them, say they do not have a lathe to check them

Over heating them just makes it worse...

Had to change a wheel cylinder due to excessive out of round, cylinder started to leak

Was planning on purchasing Raybestos Premium drums in a week and taking the wear-ever back for a refund

I believe they are simply junk drums that are not round to begin with

I did manage to get one drum, that seems to be round out of 8, but it'* not balanced correctly.. Can not win

Pull the brake shoes and put the drum and wheel back on. Confirm the problem is no longer there. When you put the shoes back on, make sure you use a new spring/clip kit and dissasemble/clean/lubricate the adjuster. Make sure everything is properly seated. Back the adjuster way off, then put the drum and wheel back on. Accessing the adjuster through the back plate opening, slowly turn the adjuster to move the drums out until you feel contact, then back off the adjuster a little until there is no contact.

Rotating the wheel without the brake shoes will tell you whether this is a brake related problem or not. I would normally suspect an out-of-round drum, but you have pretty much ruled that out with what you did so far. If it is related to brakes, it comes down to an improperly installed component, a stuck and/or improperly adusted adjuster, or the park brake hanging up.

There is no wear spots on the backing plate at all, so the only place for it to be rubbing is the brake shoes.

I may just have to bite the bullet and go for a LR hub, even though that is a very annoying prospect.

It'* the Drums

they are out of round

out of box

also, on the brake springs.. where they enter the shoe, take a hammer and screw driver, and tap them in, sometimes they do not go in properly when installing

but your scrape noise, is the drum being out of round, and will only get worse

you could have the drum turned on brake lathe ... but will cost you about the same to return old one

Purchase another, or both.. and return the warped ones

I ordered some premium drums.. will install in a few days

I have been battling this issue too, when I did finally got a round drum, it'* out of balance

I think the drums are round, because each side acts exactly the same, no matter what drum is where.

I hate doing jobs twice :(

try this