advice needed - drive shaft seal

[dajohnson53]

Hi: I've posted regarding my '74 Merc 110 (9.8 hp). Look soon for a progress report on my first carb clean/rebuild!<br /><br />RE: the lower unit. When I bought the motor last year, the lower unit oil looked good, compression was good, and it ran pretty well, so I bought it. After trolling for a few days, when I went to put it up for the winter I noticed water in the lower unit. It wasn't a drain/fill o-ring issue, so I had a shop look at it. They pressure tested it and replaced the seals. When I picked it up they said the drive shaft was corroded and wouldn't make a perfect seal, but it was pretty decent. They got it smoothed out as best they could and reported that it would hold "about 10 lbs. of pressure - but we like to see 15". <br /><br />I have no idea if these numbers are good or not. But... they also said that my best bet was to just keep my eye on it and if the oil showed water intrusion to just change it regularly and frequently. Unless I luck out and find a good used drive shaft, it can't be replaced.<br /><br />Since then, looking at old posts from this forum, I see that there's actually a couple of options: speedi-sleeves and some sort of welding and machining process to put it back into spec. My understanding is that the speedi-sleeve process is likely to be a long term, if not permanent fix (although this mechanic "doesn't like them") and the other would be a permanent fix.<br /><br />In the mean time, I ran it in a tub of water, in gear, for about 1/2 hour this weekend and drained and inspected the lower unit oil. It was perfect - no cloudiness or other signs of water.<br /><br />What do you think? Do you think I have reasonable seals? Is it likely that my 30 minute test indicates that I won't be having a significant problem with water intrusion? <br /><br />I wouldn't mind spending a "little" more money on the engine, and if I should expect chronic water problems, I'd like to go ahead and get the work done before the high season. But if this is going to be just a minor water leaking problem in the long run, I'd probably just live with it ( and change the oil regularly - I only use this motor 3 - 4 times per year, for a day or two each time).

 

[DHPMARINE]

Re: advice needed - drive shaft seal

D. My opinion is the shop should have given you options before doing the repair.I don't see myself telling a customer we couldn't make a perfect seal,but it was pretty decent.Just wonder how they describe their women?<br /><br />Speedi-sleeves are good,but a bit hard to instal on some driveshafts,because of their lenghths.Spray welding is good,but not cheap.<br /><br />Having spent the money you have,I would advise checking the oil periodically for water,and change the oil accordingly.How much $$$$ can you put into a 1974 motor ?<br /><br />DHP

 

[rodbolt]

Re: advice needed - drive shaft seal

I am with DHP. many times I have altered the sealposition or had one that was not as nice a surface as I would like. however new shafts on that motor are out and sometimes the cost of grinding and rewelding or flame spraying is out. keep an eye on the oil color after each weekend of use. if it starts leaking again it will be time for a more permmanent repair. speedi sleeves are wonderful if you can use it on your application.

 

[dajohnson53]

Re: advice needed - drive shaft seal

You guys are right - I really don't want to spend a lot of money on this thing. If it's just a matter of changing the oil a few times, no big deal. I only use this thing for all-day trolling, maybe total of 4 days a year. No daily or even weekly use. Thanks for the comments.