I have a 1988 Mercury 100 hp outboard that the trim motor will not work. When you hit the up or down switch the solenoids click but no movement in the motor. Tried bypassing solenoids per other post on board and this did not work. Battery has a full charge. So I would like to remove the unit and try and clean it. I can see the front bolt but there appears to be a back bolt. How do I get to the back bolts? Do I have to remove the transom bolts? Last question, what weight and type oil do I top off the fluid with? It is a square type motor with 3 wires and two solenoids and three trim pistons. Thanks for your help. BC.