I took the lower unit apart on my 650 Merc to see if it is worth trying to seal. I found that it is more of a mess than I had hoped (pitted gears, a small crack in the bearing carrier,a small crack in the case,etc). Anyway, I looked on ebay and found another LU off a 650 (a little newer) and the seller says the number off the inside of the case up by the trim tab is 1623-3486. The number on mine is 1623-2460. Anyone out there know what these numbers mean? As far as my LU goes, I think I will need to find another one to get all the parts I need. It is kinda a shame cause the gears look good (besides the pitting) and all but one of the bearings seem in pretty good shape. My guess is that it wasn't used very much but just neglected. I would just kinda like to know what will work and what will not in case I come across a good deal on another LU. I do not want to spend a lot on this old thing. As far as my gears go, will a little pitting hurt anything?
