outdrive leak

[bhale5]

I have a small oil leak coming out of the weephole at the bottom of the drive. I removed the lower unit to check it out , thinking that it was probably the shift shaft. There was no oil coming from there, but I did have oil where the drive shaft meets the top of the water pump and leaking down out of the drive. I was just wanting some advice on what it could be and where I should look first. It is a 1971 Merc 165 I6. Thanks.

Bryan

 

[Fishermark]

Re: outdrive leak

The seal(s) is/are bad in the upper unit. Time for a pressure test.

 

[bhale5]

Re: outdrive leak

I've never done this. How exactly is it done?

 

[Fishermark]

Re: outdrive leak

Drain the oil out of the outdrive, and install a pressure gauge, then pump up the pressure with a bicycle pump. The unit should hold 10 pounds of pressure for 45 minutes or so. (That's going by memory - if you do a search here, you will see some home made testers... or you can buy one as well).