Brake Drum External Spring

I've always wondered why Chrysler brake drums have springs on the outside lip of the drum. Does anyone know why these springs were added? Was it to better balance the drums, or maybe to reduce vibration?

See pic below for reference.

Thanks.

Rob-I think it was for a vibration dampner.Front only right?

I'm pretty sure they were only installed on the front.

I think they were on the front drums only to reduce vibrations and chatter.

Noise reduction

Winner......tap a brake drum with and without the spring with a wrench or similar steel object and you'll hear the difference. Or spin the drum with and without the spring and while it's spinning touch the wrench or screwdriver to the spinning drum..again you'll hear the difference.

MikeR

It's for if you push too hard on the brake and expand the drum. The spring will bring it back to the right size.

That makes total sense. It's a harmonic dampener.

LOL

Anyone repop them?

Try Bill Rolik, I believe he had them

ECS also has them and I saw them for sale at Carlisle at Fellwock's tent.

frank b and roger g also.