Kyosho Route 246 Front End Oil Damper Set (MR-03W)

Do not ream the ball cups out! The cups will be tight when you first put them together. You just assemble them and them pinch them with a set of needle nose pliers. Watch some YouTube videos to see how you loosen them up. I messed mine up using a tiny cup reamer; you don't know what you don't know.

The only reason I deducted a star is because to get full motion you have to assemble the front posts upside down, which makes them more likely to grab the track. It doesn't seem like they were very well thought out.