I have a 2007 seatrail boat trailer I decided to replace rear 6 inch keel roller as it was not spinning as spindle bolt was seized on I had to grind it off,I brought new spindle and roller from rtm and replaced the rear one,I noticed the size in the middle section of the roller is 5mm in diameter bigger than the original one,I was wondering do I need to replace the other 2 rollers or not I was going replace the middle roller as the spindle was rusting as well