I have a lower with casting # 1686-827214C. it has 44104A7 gear set which I am replacing. The drive shaft seal area is very worn and corroded and needs to be either replaced or repaired. My question is has anyone had any experience with having these seal surfaces repaired. I can have it done fairly cheaply by my friend who has been a machinist for 40+ years and is excellent at his trade. The other option is to replace the shaft, but if I'm looking at the right parts breakdown the shaft is about $1100.00 retail. Can someone tell me the difference between this shaft(848449A4)and the 897624T shaft, used on most 2.5's? Also Maybe I'm looking up the wrong lower unit, so please correct me if so.