I replaced the antenna mast with one off of ebay through a link I found on a few threads here. I removed the old mast and there was no nylon strip anywhere to be found. I put the new mast in following instructions found on here and everything seemed good. After a couple of test strokes up and down it started to make a grinding noise when going up only. Then it started to stop just before it made it all the way down and struggles on the initial start on the way up. The motor sounds strong so I'm not sure what's going on.