Mercury 40 HP 1982, Lower Unit Stuck

I hesitate to even reply, because all of the folks helping you already know 1,000 time more than me and probably would have already mentioned this if it was applicable, but here goes...

On my 1987 25HP to remove the lower unit there was a connection at the end of the shift shaft up in the middle of the engine, right behind the carburetor. It was connected with a cotter pin like connection. My lower unit would only drop down about 2 inches when it was connected. When I figured that out it slid right off. None of the other motors I've ever owned required anything to be disconnected at the top of the shift shaft so I figured I'd mention it where it stumped me for a little while.

Good luck,
Rob

The brass piece you see here is what the shift shaft connected to. The blue piece in the first picture connected the shift shaft to that piece and had to be un-clipped before the lower unit would drop.

You seem to run these beauties a lot longer in the states than we do in the uk our water must be saltier! Being an old timer I used to get this problem a lot. As was mentioned in an earlier post drill that hole in line with the drive shaft just under the power head use a large flat punch and give it a bit of welly turning the flywheel quarter of a turn at a time it apply some pressure to the gap in the gear case it should come. As a last resort make a bigger hole and cut the drive shaft remove powerhead and make a tool to remove the cut off shaft and start rebuilding the gearbox with a new drive shaft.
hope this helps