Gearcase leak…where? how?

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  • wedgie


    Replies: 1041
    Topics: 78

    Mumbles


    Replies: 5764
    Topics: 298
    #248290

    https://www.aliexpress.com/item/32997552741.html?spm=a2g0o.store_pc_allProduct.8148356.57.4e4a3791Awb8Iq

    Hey Wedgie, good to see you but being for a Parsun, those seals might be 8 or 10mm instead of 3/8″.

    Anyone have a Parson to verify?


    fleetwin

    US Member - 2 Years
    Replies: 4737
    Topics: 46
    #248298

    and refill with OEM quality gear lube…

    Any suggestions what should be used? In ’57, the OEM said OMC type C which, if I’m not mistaken, was SAE90 gear oil. Lubricants have come a long way since then…is there anything wrong with the WestMarine 80W-90 Hi Viscosity marine gear oil that I’ve been using? Is it not “OEM quality”?

    I know there’s some gear oils available that are specifically marketed as “Type C”….but they all say that they’re for electric shifting, which I don’t have. Does it matter? Should I be using this?

    Don’t overthink this too much, looking for issues that might not be there…

    That may be the best suggestion of all! …and I thank you for it!

    One last thought: the more I read, the more I find people saying “never re-use the plug washers”. Guess what I’ve reused? 🙂

    But as I look over the ‘net, I’m not seeing a real clear picture of what washer to use. The plastic ones seem to be the most common, but I’m not certain which to buy. Johnson part # 27-284 is the correct-but-obsolete OMC number. What is a modern, plastic equivalent? Is it Sierra 18-4248-9? As absurdly overpriced as these are, I’d prefer not to make a purchasing error .
    .

    Theoretically, they should be replaced everytime, but it is rare that this actually happens. And, it is rare that they actually leak…But, it surely is possible. Like I said, the biggest issue is inadvertently having two washers in one hole, and none in the other…Or, perhaps adding an extra washer when there is already one hiding in the housing cavity…You would have seen oil dripping on a hard surface below the gearcase if the lower washer was an issue…Not so much with the upper washer though…Again, please get a good look inside those cavities using a pick to make sure a washer isn’t hiding in one/both of the cavities in addition to one that might be on the screw.
    There were a few different of these washers used back in the day, didn’t mean to blanket prescribe the 311598 which might be a tad too big for some of those RD/Bigtwin/40hp gearcases. What year/hp is your engine?


    nj-boatbuilder57


    Replies: 286
    Topics: 41
    #248305

    ’57 Johnson Javelin 35HP

    The upper plug…which needed to have my compressor fitting really tight to eliminate bubbles…had a plug with a white nylon washer in good condition.

    The lower plug (no bubbles, not leaking for the test…but I opened it to drain the gearcase and re-seated it for the test, so that’s not necessarily indicative that it was sealed while boating)…it has the remnants of a fiber washer mashed badly into the gearcase opening and will require some surgery to get it all cleaned out.

    Any thoughts on my previous question about gear oil to use?


    wedgie


    Replies: 1041
    Topics: 78
    #248320

    Hi Mumbs

    Doh! you’re right of course. I ordered some for my neighbours 1993 Yamaha 9.9 , and forgot they’re diff size

    • This reply was modified 2 years, 5 months ago by wedgie.

    crosbyman

    Canada Member - 2 Years
    Replies: 3588
    Topics: 326
    #248331

    Any thoughts on my previous question about gear oil to use? regular 90 grade marine oil should do .

    Joining AOMCI has priviledges 🙂


    Mumbles


    Replies: 5764
    Topics: 298
    #248353

    OMC Hi-Vis was the stuff to use when it was available but any 80-90 gear oil rated for marine use will work just fine in your non-electric shift gearcase.


    fleetwin

    US Member - 2 Years
    Replies: 4737
    Topics: 46
    #248356

    http://www.marineengine.com/parts/johnson-evinrude-parts.php?year=1960&hp=40&model=35019&manufacturer=Evinrude&section=Big+Twin+Gear+Case Item #64

    I point out this different part number for the drain screw washers used on some of these gearcases only because I had an issue while working on one….The standard 311598 washer would not fit very well into the lower fill hole, its OD was just a tad too big…And I could tell the washer was not going to seat properly….Finally looked up the actual part number and found that it was 307552 and had not been superceded to the standard 311598….
    So, if the 311598 won’t fit into the cavity relatively easily, order the 307552 washers…


    nj-boatbuilder57


    Replies: 286
    Topics: 41
    #248586

    Is the 307552 available as a nylon washer?


    nj-boatbuilder57


    Replies: 286
    Topics: 41
    #248595

    I think I may have had a “eureka” moment today…and it dovetails with fleetwin’s post above: A gasket is a gasket & a screw is a screw, right? Not so fast!

    Unlike most of you, I’ve had…over the years…a few ’50s and ’60s engines, but right now I only have one. My “pieces & parts” drawers are not as extensive as yours…so all I seem to have are four (4) plugs, and they’re all different head diameters:

    At this point I can’t tell you which 2 were in this engine and which were in my parts drawer. But what’s even more interesting is my gearcase: the two race holes are not the same size. Yes, they’re both 3/8-16, but the race where the washer & plug head seat are different.

    Lower plug hole race: 0.546″

    Upper plug hole race: 0.610″

    I have only one (1) plug that fits my lower…the 0.534″

    …but my 0.546 plug will not fit in my 0.546 port.

    It is entirely possible that my “seal” was metal-on-metal and the washer wasn’t compressed at all. This could be the source of my leak

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