I have been using pennzoil gear lube that is marine grade, bought at walmart if that helps. I do have a good stream of water coming out the hole on top if that helps also, I could change the impeller as its been awhile. The last time I changed the impeller was a few years ago and that was when my problem started. The motor was ran for about 30 seconds out of water and ruined the impeller. How would that be connected to the problem I am having now? I know the prop turns easily so I doubt the bearings in the lower unit are bad but maybe as SF said it could possibily be the upper shaft bearing. I have been going two years on the oil change and I wonder if a bearing would hang in there that long, I wouldnt think so. I have felt the lower unit temp by hand after it has been ran awhile and it has always been similar to the water temp, definatly not much warmer anyways. I would like to get this fixed before anything major breaks thats for sure. Is there any way that the exhaust can get into the oil where it may be getting sooty? Thanks for the help guys.