1986 Merc 115 lower unit OK driveshaft looks OK no power at prop Tell me the bad news

" Hi,

My 86 Merc 115 wa

" Hi,

My 86 Merc 115 was working perfectly, and was being operated in gear when I heard a clunk and the engine raced. I pulled the throttle back, and noticed it was no longer pumping water.. made it to the dock on the kicker.

Pulled off the lower unit expecting to find a snapped/stripped driveshaft and found nothing. The lower unit will shift into gear and the prop turns when I turn the driveshaft. I put the lower unit back on and turned the flywheel by hand, with the engine in gear - nothing at the prop. The splines on the driveshaft look worn, but not stripped, I found some small metal shavings on them, but it really didn't look like it came from the driveshaft. Does this sound like the fitting where the driveshaft is connected to the camshaft? Is it possible that a driveshaft that only looks worn could slip this easily? If it is the fitting on the camshaft, is this replacable?, is it common?, and what does it take to replace? Thanks for any/all advice,

Jon "

" Hi again,

By putting

" Hi again,

By putting the lower unit back on, and shifting it into reverse, and then turning the prop, I can hear the splines sliding over whatever junk is left in there.. clunk clunk clunk. To me this means the crankshaft needs replacing or I need a new OB.. I'm thinking of attempting it.

From what I've read, replacing the crankshaft means more or less taking everything apart.. The compression on this engine is 124-130, would it be possible to just do that and then swap parts? What type of cost am I looking at in parts to do it? Is there anything else that should be replaced at the same time? Thanks again for any/all advice,

Jon "

" I'd bet that the metal s

" I'd bet that the metal shaving that you found on the driveshatf were the splines from the crankshaft. You would most likley need to change the crankshaft, but first find out what cuased this so it dosen't happen agine when or if you choose put a new crank in it. Josh Hildreth "

REMOVE THE LOWER UNIT AND SHI

REMOVE THE LOWER UNIT AND SHINE A FLSH LIGHT UP TO THE CRANKSHAFT. YOU SHOULD BE ABLE TO SEE DAMAGE IF THERE IS ANY. BEFORE YOU TEAR DOWN THE POWERHEAD CHECK THE OIL IN THE LOWER UNIT FOR METAL FILINGS. IT IS MUCH MORE COMMON TO HAVE A GEAR FAILURE THEN A STRIPPED CRANK SPLINE. MIGHT SAVE A LOT OF UNNECESSARY WORK.