I have this trimmer and it works fine, I think I have used it for 8 years. My question is the bottom gear where shaft meets the spool. Seems to be getting hot, maybe that is normal. Also there is screw that is apparently a drain plug. Does not appear to have any other function so I assume it must be for gear lube. When I removed and turned upside down nothing came out. Just wondering if anyone has knowledge of this drain plug if that what it is. Otherwise I would guess the whole assembly is replaceable, does not appear that you can remove and replace any parts.
My Ryobi straight shaft had the pinion gear at the bottom. At about year 8 I was cleaning and lubing the drive shaft and disassembled the end. If yours is like mine it was not difficult. I cleaned the gear set and packed it with disc brake wheel bearing grease for lack of other. It ran well another 2 years 'til the engine quit. I tried to put a little zerk fitting into the plug hole but determined is was not SAE , perhaps metric so next year I pulled the plug and butted a grease gun tip against the hole and pumped. Seemed to work well.
I did put some high temp grease in, ran it for a bit. I did get grease to come out next to the output shaft, I guess I know there is and was grease in it.
