Running the boat recently, lost all propulsion. Revs were fine, clutch seemed fine, but no go.
Completely bummed, lots of time waiting for tow back to ramp, thought about selling the thing for what I could get for it. Decided to open it up, and the spline connect from powerhead to lower is completely stripped.
Anybody else have this happen? Now I'm looking for the schematic to drop the lower, all I can see down the tower is a brass square head on top of male spline, and a bunch of gunk at the bottom.
Any ideas on how to keep this from happening again?
Motor is strong, but not a dyno buster.

very easy to drop the lower unit from the powerhead and change out the mid section. Im not sure you can change out just the spline shaft.
I just did this exact thing to my engine about a month ago.
What year motor are you working on>?

07, have a new hub coming now. The driveshaft spline was still in tolerable condition, I am going to talk to PD and see if I can cut the spacers down a bit and drop the hub spline another 3/8-1/2" onto the drive shaft.

it happens. if you run it like a mudmotor for 13 years, you will break stuff!!!! lol

i've stripped out a few over the years. no biggie. good luck with the repair!!!

That seems to be the consencus. Thanks guys, parts are on the way.

I had the same thing on my 37 PD ! First thing i noticed was the top of the spline was only 1/3 of the way worn , For some reason it had not been seated , would like to know If any one else has seen this ?