Johnson 6hp 1967 Outboard Gear Case Part 4

Welcome to part 4 of a series on my Johnson 6hp 1967 Outboard Gear Case (part 1, part 2, part 3…).  The short story is I wasn’t successful at removing the old oil retainer on my own 😛  It’s really stuck in the impeller housing and retainer assembly (382796) and I have to be careful because Evinrude / Johnson no longer produces that housing!  Now you get to learn from my struggles.  In part 5 you’ll see I was sort of doomed because the last person used Red high-strength loctite and really sealed those old oil retainers in the impeller housing and the propeller shaft bearing!

Advice on removing Oil Seals / Retainers

Once I had a mess on my hands and a better sense of what didn’t work, I started looking around the internet to see other people’s techniques and to discover if there’s anything I could have done better (even though I was probably doomed by red loctite).

This fellow has a pretty rough manner with his engines, but I like his straightforward technique for removing an oil seal.  It certainly appeals to someone that doesn’t have a big shop and lots of fancy tools.  But I think it would have damaged the soft zinc / aluminium impeller housing on the Johnson ’67 outboard.  If you look at some of my photos in the other posts you can see the last mechanic was a bit rough and chipped the inside of the impeller housing.  I don’t want to worsen that so I’m trying to avoid pushing on the soft zinc housing.  You want to jump ahead to minute 6:15 in this video:

It makes me feel better that this guy also uses the drill and screw technique to pull his old oil seals:

His taping method is probably better than the straight pull I was putting on mine.  But again there was just too much locktite on mine, or the old oil retainer (300599) that was already in my engine was just a bit too big for the space, or both.  It certainly looked like someone else had chipped the soft zinc impeller housing in the past trying to get an oil retainer out of there.  Or perhaps it’s just the nature of this Johnson 1967 6hp design to have a really tight fit?  But as I mentioned I didn’t really want to chip up the zinc housing any more, so I focused my force on the screws in the oil retainer itself.  Perhaps the previous mechanic used this technique to fit this damn oil retainer in there!  haha

More seriously, this fellow seems to speak from experience and has a very precise technique for installing the new oil retainer to avoid rolling the rubber seal.  I notice that he also uses a jiggle / tap to get the old oil seal out – Something I definitely need to remember for the future.  I also think his advice about using lots of grease to avoid burning / seizing the rubber on the first run is very important.

This guy has a good technique for removing bushings. Given the shape of the impeller housing it wouldn’t work on my oil retainer for the ’67 Johnson 6hp, but I like the logic and simplicity of this technique:

Now, I’ve had to deal with this impeller housing before in the series on the water cooling system in part 3.  And my Dad’s neighbour, who is a mechanical engineer that worked for Johnson briefly in the early 1970s, used a small handheld propane torch to apply some heat to the steel/brass parts that pass through the zinc / aluminium housing in order to loosen them up.  Risky business when there’s no replacement part, but I’m sort of at the end of the road here and it seems less risky than trying to cut through the brass retainer without cutting into the zinc housing.

Car mechanics are lucky they don’t have a soft zinc / aluminium housing to work around!  As an aside, I really like Scotty’s video style here, the monologue is really well edited:

But for my problem I want to think of heat more in an induction sense. I’m not recommending this system for the Johnson ’67 oil retainer, it’s overkill, but I think this example of induction heating gives a better vision of what you want to be thinking about when you’re using the propane torch:

Next steps were to buy a torch and beg Sam and Lloyd Rooke to help a brother out again, and see if they have steadier hands when it comes to this tricky work! Stay tuned for part 5.

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