When installing these pillow block bearings I noticed that they rocked side to side and up and down. At first I assumed that there was play in the ball bearings.. This wasn't the case once I removed the locking ring and the bearing just fell out, then I found that the holes were too big and the bearing itself was the cause of my sloppiness the block unusable for me it's me i'll leave them one day to open up the hole and use it with the 3/8th bearing i have linear bearings aren't bad per se a bit noisy in my opinion but... will work fine.