RMS REAR SUSP.

Sounds like you need to check the installation and make sure everything is assembled properly and tight.

If the tires hit the quarters then clearly they don’t have plenty of clearance, or something isn’t working as it should. What’s “plenty of clearance”?

Pictures would be very helpful
The tightest spot is in the back The left side has about 1/2 inch The right side has about 5/16