[THEFERMANATOR]

Originally Posted by Kracker Jack

Fellas I must ask. I've replaced a lot of waterpumps in my life and yes its a pretty easy job. But what is the deal with the o-ring at the top of the shaft the goes into the power head? And do you need it? My lower unit came of with out one. I did the coat hanger trick to try and get it out with no luck.

It's to help keep grease on the driveshaft splines and prevent saltwater from getting in there and seizing them together. Without it the grease will wash out and the splines are likely to seize into the crank leaving you with a 1 piece engine that can't be taken apart. I've had one like this in the past, and MJ had one as well.