1995 Mariner 25H.P. propshaft seal

[chopper]

I have a 1995 25H.P. Mariner serial #OG156904 its been leaking gearlube from behind the prop for the last three years(Dime to fifty-cent size on concrete)after every use. I have changed the lower unit lube every year and checked periodically and never observed any milkiness. Drained lower unit and took off prop today. Thought a rookie like me could maybe change that seal. NOT! Will I have to drop the lower unit to do so? Anybody got any tips, or should I not even worry about it. Chopper

 

[alcan]

Re: 1995 Mariner 25H.P. propshaft seal

Hi Chopper<br /> Actually I believe there are two seals on the prop shaft. Installed back to back.I don't think this would be too bad a job for someone who is moderatly inclined. The first thng I recomend to do is obtain a manual that covers this procedure for this motor. The second thing to do is presure and vacuume test the unit. This will tell without a doubt if you indeed have a leak. You will need this capablity anyway To tell if your repair was successful. No you would not have to drop the gear case in order to change these seals. How ever you may as well service the water pump while your at it. Also try to determine what caused the seals to fail,fish line,bent shaft,etc. This oil dripping, is it clean looking (honey like) or is it black and nasty looking (dirty)?

 

[chopper]

Re: 1995 Mariner 25H.P. propshaft seal

Thanks for the reply Alcan!I would like to try this myself.I'm assuming one of those"Clymer Mercury/Mariner outboard shop manuals" of the appropriate yr.and hp.as offered here on this site would walk me through this??? As for the oil that leaks out.It is very black and dirty looking!What does that mean? Thanks,chopper

 

[Walker]

Re: 1995 Mariner 25H.P. propshaft seal

Chopper, the oil spot you are finding is probably unburned oil from your fuel that accumulates in the exhaust and when you park the boat this stuff drips from the prop exhaust a little.

 

[chopper]

Re: 1995 Mariner 25H.P. propshaft seal

Thanks Walker! That would make sense then why I never have milky looking oil.That saves me an unrequired headache! Chopper

 

[alcan]

Re: 1995 Mariner 25H.P. propshaft seal

Yep, I agree with Walker. Black and nasty, your good to go. It would still be a good idea to grab a manual some where. The after markets that Iboats sells are all dandy. Another thought is to try your local library. Reading manuals isn't exactly exciting, but the more you know about your motor the more you will enjoy it. Check your prop shaft often, and always reinstall it using prop shaft greese. The stuff is sold under many different brand names. Just ask your local marine dealer,they'll get you the right stuff. I my opinion abandon fishing line is a top ten killer of outboards.