lower unit seals

[threestar]

I've found the dreaded water in my lower unit. From what I can tell, its likely the seals below the water pump and on the prop side of the shaft. Doesn't seem difficult but ...
Any helpful hints, potential pitfalls or other issues anyone can recommend I watch for?

Thanks in advance - Rob

[Ken]

Rob,
You may just have fishing line wrapped around the prop shaft and cutting into the prop shaft seal.
Remove the prop and inspect. If there is line there, carefully remove by "unwinding" and pulling gently. Sometimes the prop shaft seal will re-seal itself.
Good luck [img]smile.gif[/img] ,
Ken K

[threestar]

Ken - thanks for that - I'd read a previous note on this forum about suggesting the same but unfortunately I won't get off so lucky. Putting some pressure on it with my little mityvac, I can hear air escaping from the top of the water pump!

[Ken]

Rob,
Well, it does sound like you have a handle on the problem, and changing the seals is not too difficult - I watched my trusted marine mechanic (the one I go to when I am in over my head) rebuild a lower unit on my buddie's C115, and the best I can remember he just used a couple of regular bladed screwdrivers to pry the old seals off the drive shaft (but don't quote me on that).
I do remember there are two identical seals that are together and the "cup" side is suppose to face out, according to the manual, but my mechanic said he has found it best to have the inside seal cup facing inward and the outside seal facing outward . Hopefully someone with more knowledge than me on this will chime in and add their two cents worth.
Good luck [img]smile.gif[/img] ,
Ken K

[slim]

ken. they all have there own little way of putting seals in but the reason why yamaha wants theres both facing out is they want two seals preventing water getting in. they arent worried about oil getting out and rely on the owner and owners mechanic to check the oil level regularly to make sure it is full. in my opinion and the way i put my own in my lower unit both times i bent my propshaft was both seals facing out or as you said "cups out". as for this lower unit that needs new seals under the w/p. after removing the water pump and plate, i usually like to take the upper bearing housing out if possible. this makes it much easier to get seals out without damaging the drive shaft and much easier to install after you have the bearing housing all clean. plus you can clean the outer oring and grove on it also if you get it out. to try getting it out, unbolt the 4 bolts and with two very big flat blade screwdrivers, place them under the bearing housing top lip and pry up against the lower unit. sometimes it just comes right out. good luck and let us know what you find.

[Ken]

slim,
Thanks for that clarification on the seals.
Yeah, my personal opinion on the seals facing in or out is that there is more pressure with the water trying to get in than there is pressure trying to push oil out.
So, if I ever have to replace the seals on my little C115, I think I will face both "cups" outward.
Ken K [img]smile.gif[/img]