Rubber seats between coil or leaf springs and the body or axle.
Spring mounts cushion the contact points and reduce noise. Wear or loss of material can cause creaks, knocks and small changes in ride height. Match inner and outer diameter, thickness and locating features. Inspect the mating surfaces for rust and sharp edges. Correct mounts help the suspension work quietly.
Dry or worn spring mounts can move and create noise.
Badly worn mounts may change how high the spring holds the body.
Many workshops fit new mounts when replacing springs or struts.