40hp Merc lower unit problems

[Chandos Bass Bay]

Our eary 90's Merc 40hp Classic 2-stroke is getting water into the oil in the lower unit. When I took the boat out this fall and drained the oil out of the lower unit it was milky white. I rinsed out the chamber with fresh gear oil and refilled it. I then hooked up the "muffs" with the garden hose and ran the engine for another couple minutes. When I drained the oil to check the colour it was milky white again! What is the problem? Obviously the water is getting into the oil chamber through the intake on it's way to the engine, but before I take the lower end off I was hoping someone could help me diagnose the problem.<br />Thanks for any help!<br />Tim

 

[Laddies]

Re: 40hp Merc lower unit problems

The seals unde the w/pump are leaking

 

[Chandos Bass Bay]

Re: 40hp Merc lower unit problems

Thanks, I should purchase a seal kit for the water pump then?

 

[Laddies]

Re: 40hp Merc lower unit problems

If the water pump impeller has not been replaced lately I would get a impeller repair kit it has the imp and gaskets plus the o-rings you will need plus the 2 w/pump seals seperately

 

[Chandos Bass Bay]

Re: 40hp Merc lower unit problems

thanks very much, i'll get it all.<br />Cheers,<br />Tim

 

[Moody Blue]

Re: 40hp Merc lower unit problems

As I learned first hand, change the shift shaft seal while you are in there. I had a similar problem and only changed the driveshaft seals under the water pump. Still had water getting in after that. Took it apart again and changed the shift shaft seal and everything is now OK. The seal is only about $20 so its worth changing it all at the same time.

 

[Chandos Bass Bay]

Re: 40hp Merc lower unit problems

Thanks, will do.

 

[DHPMARINE]

Re: 40hp Merc lower unit problems

Actually,since your motor is past 10 years old,look at replacing ALL the seals.They are ALL 10 years old,and tired.<br /><br />DHP