Lower unit leaking Johnson 6

[gnarbrah]

I just noticed a small drip of lower unit oil coming out from behind the prop on my 1975 Johnson 6hp. Just wondering if there are any tricks I need to know before I go tearing it apart. In all actuality I've never done it so if anybody can give me step by step I'd really appreciate it! Thanks for your help!

 

[HighTrim]

Re: Lower unit leaking Johnson 6

Are you sure it is oil and not simply carbon, an unburnt fuel / oil mixture? Check the following link for more reading on this.

http://forums.iboats.com/showthread.php?t=207285

Check the level of the fluid to verify if you are in fact low. Its colour will also tell you if you have water intrusion. If you do in fact have a leak/water intrusion, you could pressure test the lu to find the breach or simply re seal the entire thing. A manual would pay for itself a million times over here.

 

[Vic.S]

Re: Lower unit leaking Johnson 6

Surely it will be easy to tell if it is lower unit oil or a gungy black mix of carbon and unburnt fuel/oil. If it's lower unit oil and it's coming from behind the prop its the seal on the shaft that needs renewing

On my later model the prop shaft seals are in a removeable housing but that is not so with a '75 model.

I dont know if this will work but often it is possible to pull seals out by drilling a couple of small holes, threading in a couple of self tapping screws and using those to pull the seal out. If it works it saves a lot of work.

 

[gnarbrah]

Re: Lower unit leaking Johnson 6

My local library has the shop manual but can't check out reference materials. I'll go check ebay now and just bite the bullet and buy one. I don't plan on getting rid of the motor so I'm sure its a wise move anyhow. I guess thats the best place to start. Its definitely oil, I just changed it and its that clear brown that it should be coming down (very slow I might add) I did however pull the plugs to top it off before using it last weekend and the oile that dripped out of the lower hole was milky. I'm assuming this means there is water getting in? Is it death to the lower unit if I run it like that or if I change the seal in a reasonable timeframe will I be ok?

Thanks

 

[HighTrim]

Re: Lower unit leaking Johnson 6

You do have water intrusion. Sounds as if it is the prop shaft seal as stated. Put in new synthetic lu oil, new gaskets on the drain and vent screw, along with a prop shaft seal, then re check it after a test run for more milky oil.

Hopefully that nips her in the bud.

 

[gnarbrah]

Re: Lower unit leaking Johnson 6

Thanks - thats what I suspected and as soon as I get the manual I'll be tearing her apart!