Now that I am thinking about it, I did work on a car once that did not have those retaining clips. It had a large U shaped clip that locked into the backing plate at each end, and locked under the brake shoes to hold them in place to the backing plate. Looking up the hardware kit for your vehicle (More Information for WAGNER H7203) I see a clip similar to what I am talking about. Do you have this style of clip, and is it in place?

The drum brake hardware kits for your car do not show the retention clips I thought would be there.

Yes, that is the W shaped spring/retention and light weight springs, there is nothing else other than adjuster screw jiggy and emergency brake bracket behind shoes ... the W spring clips in at bottom and you have to pull out on the ends and there are holes in the shoes it falls into and holds the shoes in place like a retaining clip would.. so the big W looking spring is actually the retainer and a spring

so..any ideas?

There is only so much in there that can cause this. Missing clips, loose components, improper adjustment, warped drums, or a warped hub. Are there any signs the backing plate is bent and rubbing somewhere. Other than that, I think the only thing you haven't ruled out is a warped hub.

Its coming from both sides so it is not related to the E brake.

The only thing left back there is the hub that turns. I think somebody roasted the brakes back there by leaving the ebrake on.

I would think they would have to have been glowing red to warp a hub

They could have been, before you owned it. There is no telling though, which is why i gave up on mine. If you have done everything I have with your brakes, the only thing left spinning is the hub. Mine only does it on one side, so i had the luxury of swapping around drums that i thought were bad, only to find them working as they should on the other side.

if a hub got that hot, it would seize up and ruin the bearings... no way this thick hub would warp like that.. also note, it does it less often when it is raining

Just for the heck of it, find a parking lot or someplace where you can back up in reverse for a 100 yards or so dragging the brakes the whole way, as the self-adjusters work in this mode, you may at the very least be able to rule them out as the cause of the noise.

2004 Bonne SLE
1971 Chevelle SS