Oil out, water in on merc 135.... any suggestions welcome

[AndrewB]

Hey guys,<br />Ive got a 135hp 1986 black max v6 merc. Just recently I noticed a slight weeping oil leak in my lower unit out of one of the two 4-5 mil holes that are situated upwards and towards the bow of the boat in relation to the water intake. Being new to outboards I was a bit concerned and decided to drain the lower unit gear oil and found upto 1 liter of water in it, however it wasnt the milky situation I have read about in all of the prior posts on this forum. I was just wondering if anyone knew what seal I have done? hopefully its just a problem with the fill and vent screws but I fear otherwise after the leak! From the situation and my newly found knowledge after reading the manual from front to back, and back to front, would it be correct to assume it would be the shift shaft oil seal, or am I way off? If I am right, what would I expect to pay to fix this, is it cheaper to remove and take only the the lower unit to the shop, or is it not worth it, should I pressure test it first? any suggestions I'd appreciate.<br />Cheers Guys.

 

[SpinnerBait_Nut]

Re: Oil out, water in on merc 135.... any suggestions welcome

I would think that if the fill seal was bad you would have grease leaking from there also.<br />Don't know for sure but seems like it would.

 

[AndrewB]

Re: Oil out, water in on merc 135.... any suggestions welcome

Spinner_bait Nut,<br />It may be the fill or vent seal but this wasnt where it was visibly leaking from. There are two other little holes above the vent screw which I have know idea what they are there for, maybe theyre only on mercs??? Anyway I am "assuming" that if they do lead anywhere it would be into the chamber where the lower shift shaft and seals are, hence that seal - but one again, I dont really know.

 

[DJ]

Re: Oil out, water in on merc 135.... any suggestions welcome

AndrewB,<br /><br />What you may be seeing is exhaust residue draining down inside the exhaust tower. It will typically be black and oily. The holes you describe are water drain holes.<br /><br />Typically, L/U fluid will not leak out. It may sometimes leak (visibly) around a propshaft.<br /><br />I would change the fill and drain screw seals (they're cheap and easy) and refill and run it.<br /><br />If no more water shows up in the L/U-you're OK.

 

[AndrewB]

Re: Oil out, water in on merc 135.... any suggestions welcome

djohns19,<br />Thanks heaps for your reply, I havent seen any other leaks except for this one out of the little hole so Ill change the fil and vent gaskets and hopefully that will be the end of the water. Ive alrady got the gear, just thought it would prove to get some opinions first. It didnt even cross my mind about exhaust residue, I hope your right,<br />Cheers

 

[AndrewB]

Re: Oil out, water in on merc 135.... any suggestions welcome

I'm back,<br />Filled lower unit and replaced vent and fill gaskets and tilted up the motor overnight to put a little more pressure on these points. What I found was a tiny tiny leak from the fill screw - nothing major, but it looks like there is the slightest of hair line cracks along the ridge where the skeg meets the gear housing!!!, indicating a hit somewhere along the line. It appears that it has tried to be repaired - not a bad job as you can barely notice it - but obviously the life span of the repair is near its end. Firstly can this be repaired??? and secondly what is the process involved? does anyone know what kind of materials I need or does it require the services of an expert - or conversly is it worth it at all, it leaked a less than a couple of ml over a 30 hour period?

 

[ob]

Re: Oil out, water in on merc 135.... any suggestions welcome

Andrew, lower unit can be repaired by proper tig or mig welding.I would recommend draining and removing seal carrier before having it welded as the heat generated could well do in the "o" rings on carrier.Have it undercut along fracture with burring tool to insure good weld pentetration and dye checked upon completion.

 

[DJ]

Re: Oil out, water in on merc 135.... any suggestions welcome

AndrewB,<br /><br />Yes, that can be repaired. <br /><br />However, just because it is seeping from the fill screw. Don't condemn it yet. You might have some oil left in the socket that the fill screw goes into.<br /><br />I still suggest that you run the engine and recheck. If it's too late for this year, in your neck of the woods, then leave it for next spring. Or, if you are really concerned, this IS the time of the year to get engine repairs done.<br /><br />You can weld lower units. The BEST way to do it is disassembled.

 

[AndrewB]

Re: Oil out, water in on merc 135.... any suggestions welcome

ob and djohns19,<br />Thanks for the help, I really apprieciate it, I will run it and re-assess. Hopefully all goes well, and djohn19, its about to get perfect in my neck of the woods, 29 degrees celcius tomorrow, dunno what that is in (F), regardless, it perfect boating weather!!! Thanks guys.