A while back I posted a topic "delayed shift in reverse" What was happening was when I shifted to reverse it would not engage, at first I thought it was shift linkage problem. It turns out that when I changed the lower unit oil last season I noticed that the previous owner used gear oil, now the manual for this drive (275) states 10w30 motor oil. So following the manual I put 10w30 back in. When I launched the boat this year I started having the shifting problem. I pulled the boat out and put gear oil back in and haven't had any shifting problems since,does anyone know why the 10w30 would cause shifting problems if the manual recommends it? 
