So I took my boat in about a month ago to get winterized and get some maintenace stuff taken care of. I just got a call that the lower unit had a large crack in it, I asked if it could be welded and he said that because of the size and location of the crack, and stress put on that area of the lower unit that he would not weld it and I would be asking for problems down the road. He said that water had gotten into the the lower unit and froze which resulted in the crack. I'm wondering how the lower unit filled with water, bad seal? Could he of some how got water in the lower unit when winterizing it? I would think that if it was a large crack then it would have taken alot of frozen water in the lower unit to cause the crack. He was taking the lower unit off to do some matienance work and I am just wondering if he dropped it and that is how it cracked? He also quoted me $1900 for a rebuilt lower unit and said that a new one would cost me around $4500, this is for a 1997Volvo Penta 5.7L. Let me know your thoughts.