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Holy Canvas

Lower unit question

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I've got an old Johnson 9.9 (a '77 I think). It's in great shape, and has run pretty well the last couple of summers. I pulled the lower unit plug last fall, and the oil was a little milky. I replaced the oil, but my question is this, and probably stupid but.......

Do I replace the bottom plug first, so the lube doesn't all run out, or the top plug? I've heard/read in more than one place to replace the top plug first. Is this so it's not overfull? When pumping in the lube on my little 9.9, it sure didn't seem like it needed much. If I replace the top plug first, it seemed like there wouldn't be anything left in there by the time I got to the bottom plug. Sorry for the dumb question

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To drain your lower unit oil, pull the bottom plug, then pull the top plug. The top plug holds a vacuum, so little oil runs out until the top plug is removed.

When filling, fill from the bottom plug until a clear, non-bubbly stream comes out the top hole. Put the screw in the top hole (holding a vacuum), then put the screw in the bottom hole. Filling from the bottom gets rids of any air bubble / trapped air.

marine_man

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My manual for my 78 9.9/15 says the gearcase capacity is 8.8oz or 260 ml.

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