I have removed the bolt located under the trim tab and the bolt located under the anti-cavitation plate and loosened the two nuts located on the side of the gear housing but the lower unit will not drop more than about one half inch. I hace used a block of wood and a hammer but was not able to cause the lower unit to drop at all. I have been told by a mercury service center (over the phone) that it is possible that the drive shaft has corroded into the block and must be cut in half to drop the lower unit then sent to a machine shop to have the drive shaft press out. This engine has never been in salt water and there is no indication of corrosion or rust anywhere on the motor. The engine had not been started in three years but after changing the fuel pump the engine runs well. I noticed there was no water coming from the "tell-tale" so I decided to replace the impeller. I have not been able to get the lower unit off and I don't want to cut it off before asking help from the experts out there. I'm sure the splines on the drive shaft could be twisted but is there anything I could try before cutting the drive shaft into?
