2002 4.3 mercruiser alpha one gen two. Just needed to start a new thread for a new question. I have the outdrive removed for inspection of water impeller i installed about a month ago. engine was running same temp as before new impeller. New question is should i replace the u joints while i am in there? they do not have a grease zerk, and I do not feel any problems in them now. But when we drove the boat last week my wife and i noticed it had a little more vibration than normal. I do not suspect them but I have owned the boat 2 years and have not replaced them, and dont know when the previous owner did. Thanks