Water pump drive shaft damage 1991 70 hp

[WT2]

well once again I have a potential simple problem I just don't understand. My water pump stopped pumping water as I was putting my boat in and then a loud "bad" sound came from the motor. I shut it off quickly, after I pulled the lower unit I realized that all my splines on the shaft we gone. The water impeller looks good and didn't appear to be stuck so what in the heck caused this damage and where can a person order a new shaft. I have some folks around hear that could repair the shaft but I am worried of a break later on.

 

[Haffiman]

Re: Water pump drive shaft damage 1991 70 hp

Check that your lower unit did not seize up!
Even double check the crank splines.
Reason: most likely lack of lubrication/grease unless the lower unit has seized up!

 

[WT2]

Re: Water pump drive shaft damage 1991 70 hp

Thanks. After I took the lower unit off I put it in gear and felt no resistance with the shaft turning. I had plenty of lower unit oil but it did smell like it was burned. Tomorrow I will try to tear the lower unit apart and get the shaft out hopefully I can find a bolt or a screw in the lower unit that could have caused a quick stop of the shaft. I also hope that the splines on the shaft are designed to give before the female splines n the motor. I always said I didn't want to be a boat mechanic. One of these days I will learn to keep my mouth shut!

 

[Haffiman]

Re: Water pump drive shaft damage 1991 70 hp

The drive shaft splines are rather 'soft' compared to the crank splines. However if the O-ring #58 is missing on top of the driveshaft and water (salt) enters and grease gets out, corrosion might eat the crank in very short time!!
http://www.marineengine.com/parts/j...TTLEIE&manufacturer=Evinrude&section=Gearcase

 

[WT2]

Re: Water pump drive shaft damage 1991 70 hp

I am a Missouri muddy water fellow but I didn't see the o-ring so I will look at it more close. I am glad to hear that the spline on the shaft is softer. All the cursing I give engineers this time I will give them a big thank you and thanks for the info on the o- ring.

 

[WT2]

Re: Water pump drive shaft damage 1991 70 hp

Just an update on the situation. After a long battle with the snap rings I pulled the lower unit apart and I believe a piece fell from shift dog that looks like it was broken in half. This could be the issue with the damage. I need to get an exploded view and double check but I think this is the guilty part.