6 hp Evinrude - o'ring on driveshaft

[b22smith]

I just rebuilt the water pump on my '66 - 6 hp Evinrude this weekend and noticed there was not an o'ring on the upper end of the driveshaft. Is there supposed to be one? The generic service manual implied that some models may not have an o'ring. There was nothing that appeared to show an old o'ring location either. The upper half of the driveshaft had quite a bit of grunge build-up that I had to wipe and lightly sand off so that I could slide the water pump and impeller up and off the shaft. Does that mean anything bad or is it normal for an older engine?

 

[Paul Moir]

Re: 6 hp Evinrude - o'ring on driveshaft

If there was an o-ring, there will be a cut around the splines for it to fit in. Otherwise the o-ring would just slide down the driveshaft when you pushed it into the crankshaft. Heavily lube the driveshaft with corrosion resistant grease (like OMC triple guard) to prevent corrosion and sticking.<br />Grunge is normal - mostly soot and stuff from the exhaust right?

 

[b22smith]

Re: 6 hp Evinrude - o'ring on driveshaft

Yeah, the grunge looked like hard-baked carbon deposit worst at the top to about halfway down. Just wasnt' sure if normal. There was no evidence of an o'ring groove on the shaft so I assume it doesn't require one. There is a hollow pin about three inches from the top of the shaft. I read somewhere that this pin pushes a spring-loaded seal upwards, therefore, no o'ring seal is needed. Does that sound right?

 

[Xcusme]

Re: 6 hp Evinrude - o'ring on driveshaft

Some motors had a groove in the drive shaft just below the driveshaft splines for a o'ring, some don't depending on model/year. My best guess is the o'ring kept exhaust particles from building up at the driveshaft/crank spline junction and to retain the spline grease.<br /><br />If yours has the groove, replace the o'ring and be sure to grease the driveshaft splines upon reassembly. Don't put grease on the very end of the driveshaft, this can preload the driveshaft and prevent the shaft from fully engaging the splines of the crankshaft. Without the grease, the splines can suffer metal displacement and the driveshaft will 'stick' in the crank, making future removal a real pain, and preventing a stripped crank.

 

[Paul Moir]

Re: 6 hp Evinrude - o'ring on driveshaft

All sounds right to me. You'll need to rotate the driveshaft a bit as you put the lower unit back on so that the pin goes through the slots up in the leg. You should be able to feel the spring in the seal pushing back just before the lower unit mates to the leg.<br /><br />Good luck!