25 hp Yamaha Lower unit Question.

[matt wendell]

So this past weekend my friend was out in my boat and the nuts, prop, drive shaft, washers, seals, etc all fell out of the lower unit. Has this ever happened to anyone? He claims that he didnt hit anything, but why would the whole thing fall apart?? Any help would be helpful.

matt

[Ken]

matt,
If your 25 hp lower unit is like my 2000 C115 (and I believe they are similiar), then there is (was) a ring nut that is screwed into the housing that keeps the drive shaft and gears in place.
The ring nut is held in it's tightened position by a ring locking washer that has three locking tabs on it. Those tabs are folded over into the slots of the ring nut to hold it in place.
I guess if those locking tabs somehow got bent, or if they rusted out, then maybe the ring nut could back out from vibration, but usually, corrosion after a couple of years holds the ring nut in place even without the locking washer.
Hitting the lower unit on something would not cause the prop shaft and gears to come out, in my opinion, just bust up the prop and skeg.
Good luck [img]smile.gif[/img] ,
Ken K

[jb123]

good to see you back ken....

[Ken]

thanks, jb.... good to be back [img]smile.gif[/img]