Just tore my M50 apart last night to inspect. I have 32K on the clock and I am the 3rd owner at this point. It was in great shape. I got lucky. I applied more grease and buttoned her back up. Took about an hour to tear down and put back together. Once I finished, I saw the new seal I forgot to put on sitting right next to me. Took me about 40min the second time around.