Decided this needed a new post:<br /><br />Okay, here goes...<br />Took off the leg, well drained oil first. Drained only approx 1 quart (guy I bought it from said "Just Serviced") of thick oil 
<br /><br />Pulled leg off. U-joints look strong, no play. Pulled out the shaft that goes forward into the engine with splines cut into the end (don't know what it is called). The splines are shiny and covered with metal shavings and highly worn peaks with what appears to be "spinning" damage .<br /><br />Could it spin in the coupler? Looked into coupler, don't know what I'm looking for. Lots of residue and greast. Does the shaft with splines go into coupler or through coupler and into the flywheel? Is it possible that the low oil scenario in the lower unit caused high friction in the bearings/gears which caused the excessive spline wear which in turn caused the prop to stop spinning? <br /><br />Also, lifted engine hatch and examined what I could see of the coupler. It is sandwiched in some sort of engine mount. The mount has a top piece that bolts down, like an oxen yoke. Two large bolts hold the yoke down. The bolt heads are a full 1.5 inches up ... should there be a rubber grommet there or are they loose?<br /><br />Need to check lower unit for damage due to low oil, what should I be looking for?<br /><br />What, other than negligence, would cause the lower unit to hemmorage oil (if indeed it was full recently)?<br /><br />How hard is it to replace coupler? Looks like I can remove rear engine mount and just "pop" it off and replace.<br /><br />What else do I need to look at, rebuild, or replace given the previous comedy of errors I have made?<br /><br />Thanks for reading this and if you have any energy left, please feel free to reply.
<br /><br />Pulled leg off. U-joints look strong, no play. Pulled out the shaft that goes forward into the engine with splines cut into the end (don't know what it is called). The splines are shiny and covered with metal shavings and highly worn peaks with what appears to be "spinning" damage .<br /><br />Could it spin in the coupler? Looked into coupler, don't know what I'm looking for. Lots of residue and greast. Does the shaft with splines go into coupler or through coupler and into the flywheel? Is it possible that the low oil scenario in the lower unit caused high friction in the bearings/gears which caused the excessive spline wear which in turn caused the prop to stop spinning? <br /><br />Also, lifted engine hatch and examined what I could see of the coupler. It is sandwiched in some sort of engine mount. The mount has a top piece that bolts down, like an oxen yoke. Two large bolts hold the yoke down. The bolt heads are a full 1.5 inches up ... should there be a rubber grommet there or are they loose?<br /><br />Need to check lower unit for damage due to low oil, what should I be looking for?<br /><br />What, other than negligence, would cause the lower unit to hemmorage oil (if indeed it was full recently)?<br /><br />How hard is it to replace coupler? Looks like I can remove rear engine mount and just "pop" it off and replace.<br /><br />What else do I need to look at, rebuild, or replace given the previous comedy of errors I have made?<br /><br />Thanks for reading this and if you have any energy left, please feel free to reply. 