These are the ones that mount in the suspension upright that the suspension arm bolts to. Pelican lists them under part number 204-352-00-27.

I had a similar problem with my wagon. Does yours squeak going over speedbumps even in the slightest? If so this is for sure the culprit.

The parts are inexpensive, and if you want to DIY borrow the factory tool, which is available through the tool rental link.