HD-25 and TS-20 Lower Unit Seals

[skier167]

Hello,
I’m moving along in my restorations of a HD-25 and TS-20. These are my first older outboards I’m restoring with the HD-25 being the first of the two. I’m working on seals for the lower unit/gear case and was wondering if there are any current model gaskets/seals for them? I have the prop shaft seal (Sierra 18-2035) but I’m looking for 43-300,687 and 43-301,975 I believe for the prop side of the gear case. I have gasket material to make my own but wanted to pick everyone’s brains before I go that route. Thank you for everyone’s help.

[Buccaneer]

The 301-975 part shows up as a spring, so I’m guessing that the driveshaft seal under it (300-687) is probably a leather seal,
but I may be wrong. If it’s leather, you’ll probably have to make your own. I would not look for old stock gaskets…….
probably not in good shape by now. Dealers probably have sold parts for that motor in 45 years!

Prepare to be boarded!

[skier167]

Thanks. I can’t tell if it’s leather or rubber. I know once made a tool to remove that seal but what else can be used? I attached some pictures of it but can’t tell which material it is.

• This reply was modified 4 years, 8 months ago by Mumbles.

[Buccaneer]

It’s been quite a while since I worked on mine, but I’m thinking the seal is leather,
and yours looks intact, and it might be best to leave it alone.
Those old gearcases used grease that was designed with water ingestion
in mind. Even if you were able to put a modern lip seal in there, the driveshaft
is likely to be pitted or grooved and the new seal would leak anyway.

Perhaps someone in the know will give you better advice.

Prepare to be boarded!

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skier167

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