Merc R outdrive vertical shaft grooving/wear....normal?

[bikepainter]

I was given a 79 Mark Twain 160V by my brother due to the fact he couldnt separate the lower from the upper drive to replace the water pump. After an hour or so at it I managed to separate them (stuck together with corrosion), upon separation I noticed some grooving/wear on the vertical drive shaft. I have attached a pic, it is seen here below the rubber o ring. Is this a serious issue or is this normal? If I replace the seal that contacts this area will it be ok?

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[ktbarrentine]

Pic doesn't seem to come through. (most of us use photobucket website to manage photos for uploading here). If you can catch your fingernail in the groove, then yes, it is an issue and one that has been seen before. Options include replacing the shaft, or, more simply, replacing the seal and setting it a few thou. lower in the housing so it rides on a good area of the shaft. Also, it is recommended not to replace the O-ring on the shaft because it causes more problems then it solves (like interfering with that lower seal during reassembly). On the later gens of that drive, they did away with the O-ring and the groove.
How does the rest of the drive look (you said you had corrosion). How do the u-joints and bellows look?

 

[bikepainter]

 

[bikepainter]

Thanks for the reply. Pic should show up now. The corrosion was mainly on the hidden bolt towards the front of the lower unit. I havent had a chance to check the bellows yet, but the u joints look ok to me. The upper/lower unit was already off the boat when i picked it up. I plan on pulling the engine this week or next to redo the floor, stringers and transom . I had already planned on purchasing seal kits for both halves as well as bellows kit with shift cable, along with the water pump kit i already knew it needed. I have seen several vert shafts for sale on ebay, i may have to get one but was hoping i wouldn't need to.

The boat was used regularly in the summer of 2012, but when the pump failed, my brother removed the upper/lower units and it sat on the ground from that fall(12) until I picked it up this past week.

Pics of the interiors of the upper and lower right after separation

 

[ktbarrentine]

That looks like it will clean up nicely. I've seen vert shafts in much worse shape. A little scotchbright and you can get a better "feel" for what you've got. I avoid the shaft replacement because of the headaches associated with that level of repair/replacement. At minimum, along with the water pump kit, I'd replace the seal next to the water-pocket cover (the one that rides on the vert shaft under the O-ring groove). I think you said you were already planning that. As stated before, recommend trashing the O-ring. Put a good dollop of spline grease on the splines at reassembly and should be good til next water pump replace (I do mine every two years). Do a pressure test of both halves before reassembly, and then again after bolted together, for a good warm fuzzy before putting oil in. Have fun! Sounds like a great project!

 

[dubs283]

like kt says, the shaft shows very little wear and i also have seen many others that are worse and they seal with no issue, clean it up and your good to go

when replacing the wp kit also replace the base assy and gasket underneath it