R1T's towing capacity is just over the typical 10k limit for Class IV, which is why it is listed as Class V, but uses a 2" receiver. If you have a 2" ball mount that is what you need. Most ball mounts will have a little space and can rattle around. Some ball mounts have detents or other mechanisms built in to help eliminate the sound, or you can get an anti-rattle pad, clamp, or pin to help tighten things down and eliminate the movement and noise. There are lots of options available. Check out e-trailer and see what would work best for your particular application (hollow vs solid ball mounts will use different options).
I solved this on an earlier vehicle by taking a couple of wraps around the "stump" that goes in the receiver with some aluminum foil tape (meant for HVAC ducts). Snug fit, no rattle, held up fine for thousands of miles of towing.
As mentioned above, they will all rattle a bit unless you have an "anti-rattle" pin installed. Just make sure to get one that is sturdy enough for your trailer. Amazon has a lot to offer, as well as other stores like Harbor Freight, or u-Haul.