Johnson 6hp 1967 Outboard Gear Case Part 2

This is part 2 of a series on my Johnson 6hp 1967 Outboard Gear Case (see part 1 here, part 3).  Before I get into the disassembly, I thought I’d show the seals / gaskets / washers / plugs that I’m replacing.

The first thing to note is that the 1967 CD-24D parts aren’t up on the Evinrude / Johnson website. It only starts at 1968.  I’ve found (so far) for the water system and gear case all the parts from the 1968 schematics are working.  Also for 1968 there’s a 25-A and a 25-C (plus others), and it seems that A and C are the same mostly.  If you know the logic for distinguishing these different schematics please leave a comment below.

So I’ve been using 25-A as my replacement for the CD-24D based on a recommendation from one of the marine supply shops up in Nanaimo that had an old paper manual, but that’s a hazy memory and I don’t have any documentary evidence to prove it.

Update: I got up this morning (Sun) with a fresh brain, took a look at the parts strewn around the living room, and had an aha! moment.  There is also an oil retainer in the bottom of the impeller housing that seals it off the top of the gear case housing (around the driveshaft).  I didn’t order that part yesterday!  It’s so old an cruddy that it just looks like one piece, but George Keats’ video clued me that there’s actually a removable metal housing and rubber seal there!  In this photo I think you can see the Oil Retainer (CD-25A 314167? CD-25C 300599?) in the center of the underneath of the impeller housing, and just off to the right is the smaller and lower Shift Rod Bushing (303332) that hides the Shift Rod “O” Ring (301877):

Unfortunately with the Impeller Driveshaft Oil Retainer I finally found the part of the Gearcase Group diagram (#14) where CD-25A and CD-25C actually differ.  Damn!  So now I really need to be sure of how to translate my 1967 CD-24D to a 1968 schematic number:

I’ll check out Leeroy’s site again, and then maybe email the Evinrude / Johnson corporate archives!  Drat.  I was excited for a second about this link http://shop.evinrude.com/media/document/ModelNumberReference.pdf which I think Leeroy borrowed from, but it doesn’t give any detail about those final model run/version letters for the Johnson CD-24 and CD-25.

I suppose the logic I’ll use is that, assuming the main model number increments by 1 for each year (CD-24 in 1967 to CD-25 in 1968), and assuming that the final letters are the version/run numbers, then CD-24D would probably be later in 1967 and CD-25A would probably be earlier in 1968.  So it seems there would be less variation in parts the closer the version/run.  Perhaps this theory is supported by the fact that there’s actually a CD-25C Oil Retainer (300599) in there now and I’ve been having a hell of a time with clogs in the water system and oil leaks…  I’m about ready to try the CD-25A Oil Retainer (314167).  You’ll know I’m wrong if I’m writing more blog posts about this in 6 months to a year!!  Ok, re-editing again and it looks like Leeroy and I independently came up with the same theory, “& the A could be a model revision, so this motor would probably be made in the very first part of the year”.  That’s good enough for me!

Anyhow, here are the other new seals / washers / gaskets that Sherwood Marine had in stock today (Sat).  The rest is coming from their Vancouver store later this week.

The white plugs / washers (311598) are for the flathead slot oil drain drain screws / plugs (307551) on the lower outside of the gearcase.  The small black ring (307853) is for the phillips crosshead screw / pin (308376) on the lower outside of the gearcase, you can see how the old one on the left is sort of flattened and widened.  But I never saw oil leaking out of that screw so it’s hard to imagine a lot of water getting in that way.  The big black ring (301877) is for the shift rod bushing (303332).

All in all, I think that Impeller Driveshaft Oil Retainer is the main culprit because I’ve actually seen creamy oil dripping down out of the copper water tube (304317)!

A couple of other parts were also difficult to identify / differentiate.  I was staring at the head and bearing (0382291) on my propeller shaft and wondering where it ended and the oil retainer (0313282) began…  I sort of poked from the inside / backside at the rubber seal inside the oil retainer with a small screwdriver to see if I could slide the entire metal/rubber unit out, but the rubber ring was really mushy and seemed like I should think about it some more before tearing the rubber apart without having a new part in my hand yet 🙂  Luckily George Keats and his son did a similar operation on their 1976 Evinrude and posted a great video!  My oil retainer looks slightly different than their seal, but I think it’s essentially the same design.  Thanks so much for sharing this George!

One other thing I discovered is that my shift rod is held in place by a sort of square detent spring (303466) that interacts with 3 notches in the shift rod:

That detent spring is a little hard to see here because it’s dark on dark, but it’s to the right just above the flathead slot screw that holds it in place:

Thought I’d point out those 3 notches on the shift rod and the corresponding detent spring because when I first took it apart it wasn’t easy to get it back into place and I was like ‘groan, what have I got myself into’ 🙂  But once I got a little screwdriver in there for leverage it wasn’t too tricky.  Now I really get it, and can actually remember when I was using my shifter that feeling of clicking into those 3 notches!

More in part 3 on the diassembly of the gear case and the troubleshooting.