I have a 58 chevy 1/2 ton long bed step side. On one of the brake drums there is a coiled spring around the outside that sits in a groove near the back edge. The spring is made out of flat steel that is a little larger in diameter than a wood pencil. When off the drum, it is compressed into tight coils.

The other 3 drums have the groove but no spring.

What is the purpose of the spring?

Is it necessary?

If necessary, does anyone know where these can be purchased?

Thanks: confused: