I couldn't figure out why the cobalt tile cutter freezes in the middle of a job. I finally disassembled the engine and found that the main bearing was worn and seized. Bought bearings and couldn't pull the old one off with the 5 bearing pullers I had. I bought a windshield wiper puller and immediately removed it. Inserted a new deep head bearing and voila! My $400 tile cutter was fixed for $30. The key is to read the stock number stamped on the side and then order the exact same number.