Hi! I own a 42in Fastrak Model 927350 Serial # 06091098. I am concerned about needing oil in them and in the manual it say they are sealed for life but the 44in use 20/50 motor oil. which is a little different pumps is there a way to check or a service manual out which will help me work on my lawn mower. I asked my dealer and they say 15/40 mobile one motor oil which is different than the user manual. Can you help guide me in the right direction of detailed service manual or guidance.