Johnson RDS-23 1961 40 HP upper crank seal replacement

[Rodney Owen]

Doing my first OMC refresh on 1961 40 HP.  Got all coils, points, condensers, spark plug wires, and removed armature plate.  Lots of oil beneath the plate (picture UpSeal 0 ) and I was planning on replacing crankshaft top seal as recommended by many.  I ordered a new seal but the existing seal looks nothing like the replacement.  Instructions say “use seal removal tool” and I have an email out to Richard’s Outboard Tools but it looks like he only sells remove tool for 35 and lower HP.  The other advice I see on line it to remove the rubber part of the seal, drill 1/8″ bit into brass, set screws and plug seal.  However, I don’t see any rubber part on the existing seal (picture UpSeal 5), and not sure it has any brass.  Also, my engine has a tag that say “NEW BRG” (picture) which I believe is notice that the main bearing has been replaced.  I have a picture of the replacement seal which looks nothing like the seal on crankshaft (UpSeal 6).  Looking for advice on what might be the correct seal and how to actually replace it as it appears as though I have a “non standard” set-up.  Thanks in advance.

[Sam M.]

The only advice I can give you for this is that if you do any drilling or screwing to remove the old seal, be certain not to let the drill bit or screw come in contact with the driveshaft because if the driveshaft surface (where the seal touches it) gets damaged, the new seal might not seal properly.

[Don]

Very peculiar indeed.   I would not use that drill/screw method to remove the seal, there are needle bearings under there that will be damaged if the drill bit hits them, drilling debris will damage the needles/cages as well.  It seems very odd that someone would go through all that trouble to identify a bearing replacement with that crazy tag.  The block is so discolored from years of grease and oil, but am wondering if you see signs that the block has been split apart…

In any event, I would wait for the proper seal reomover tool, then try to get the strange looking seal out of the bearing.  Does your new seal look to have the correct OD/ID so it will fit properly into the bearing/crank?

[RICHARD A. WHITE]

To help muddy the water, this particular motor uses the same seal as the earlier 35hp motors.
So my guess is that it is a 35hp block that was bumped up in hp in other ways before the redesign in 1962 to the larger crank/seal.

I looked and now realize that on my website, I forgot to list this 40 under the 18-35 seal puller info.
I will correct that error this evening.

The other question I have is… It looks like there is not a seal installed in the photo provided, or are my eyes getting that bad?
I do not have one of these motors so I have no frame of reference as to the depth of the seal pocket before or after a seal is involved.

http://www.richardsoutboardtools.com
classicomctools@gmail.com

[Don]

RICHARD A. WHITE wrote:

To help muddy the water, this particular motor uses the same seal as the earlier 35hp motors.
So my guess is that it is a 35hp block that was bumped up in hp in other ways before the redesign in 1962 to the larger crank/seal.

I looked and now realize that on my website, I forgot to list this 40 under the 18-35 seal puller info.
I will correct that error this evening.

The other question I have is… It looks like there is not a seal installed in the photo provided, or are my eyes getting that bad?
I do not have one of these motors so I have no frame of reference as to the depth of the seal pocket before or after a seal is involved.

That is what I was thinking also, almost looks like there is no seal in there, or perhaps some afternate seal was installed, perhaps upside down.   Again, I would be interested in knowing if there is visual evidence that this block has been split apart before.  Like you say, perhaps  someone “upgraded” this block somehow to the later style.  I’m not familiar enough with the differences to say for sure though.  Sure miss Frank R, he would know…

[RICHARD A. WHITE]

Upside down seals suck…. my pullers are not able to get those out…

http://www.richardsoutboardtools.com
classicomctools@gmail.com

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