Hello, 1983 mercury 4 cyl, 80hp. motor won't spit water after confirming water path is unblocked from pump to exit orifice. I dropped the lower unit and verified the impeller was good (replaced anyway). I connected a hose directly to the water tube and water immediately started gushing out the bottom of the driveshaft housing and nothing coming from the tell tale hole. I increased the hose flow and it finally filled up the system and started spitting out the hole but with most water still gushing out the housing. I understand this indicates bad seal(s) in the area around the water pipe and block. I purchased the entire 500+ page factory manual and can't even find the words "drive shaft housing" any where in it and I don't have time to read all 500 pages. The motor is mounted on the boat transom now. Is it possible to drop the drive shaft housing without pulling the power head and if so what hidden items have to be disconnected inside the cowling in order to drop it. Thanks for the help.