'58 Johnson Seahorse 10 lower unit woes

[wjteegarden]

Bought a real gem! The owner even threw in the pressure tank full of gas for free!

Cleaned her up, new gas/oil @ 32:1, a few pulls and she roared to life. Couple of quick circles, then back to the dock and ran her dry for storage.

Now the lower unit is dripping gear grease from around the prop. I plan to replace the impeller while I'm inside, but what seals/gaskets do I need to fix the leak? Also, what grease does the lower unit take? Kit numbers would help, also parts sources in NYS.

New/Old Seahorse Owner

 

[tashasdaddy]

Re: '58 Johnson Seahorse 10 lower unit woes

gear oil can be gotten at walmart. outboard lower unit gear oil, it basically is a marine grade 90 wt oil. parts on line try tcoutboards.com laingsoutboards.com sea-waymarine.com maxrules.com ishopmarine.com if you email or call them with the model # , they are very helpful.

don't know what you paid for it, but the tank is worth $80=100. to replace the hose connection new is $90. just paid $35.00 on ebay for a connector.

 

[Bob_VT]

Re: '58 Johnson Seahorse 10 lower unit woes

Your lower unit takes a whopping 9 ounces of lower unit lube. Any local Napa usually has the "marine grade" in stock in a 10 oz tube.

You will need a lower unit gearcase seal kit if the oil is from the prop shaft. You might just see years of unburned oil seeping from exhaust weep holes. I would go for the gear oil change first and check again after you have run it.

Most any OMC/Evinrude/Johnson/BRP dealer will usually keep an impellar in stock. Common item and easy to change.

Make sure you remove your old prop and check for fishing line. The newer kevlar lines and the older nylon lines will slice up a lower unit seal.

 

[fiddlinmax]

Re: '58 Johnson Seahorse 10 lower unit woes

I have a Johnson seahorse 1.5 HP (SC-10 I believe) that is leaking grease which I see on the propeller after running it. Sounds like a similar problem as above. The seals are no good right? Has anyone seen a lower unit seal kit for Johnson 1.5 HP motors?

 

[lindy46]

Re: '58 Johnson Seahorse 10 lower unit woes

Exhaust comes out just above the prop, so it may not be leaking gear oil you see. Just unburnt gas/oil mix. Drain a little oil from the lower unit and examine it. If it is milky, there is a leak. If it clear amber, no leak.

 

[fiddlinmax]

Re: '58 Johnson Seahorse 10 lower unit woes

I guess I should clarify. The grease I see is on the hub of the propeller. It is the color of peanut butter, and about as thick. If it is what I am thinking, it probably started out as white grease at one time. When I clean it off and run the motor again for 5 min or so, it shows up on the prop hub again. I need to open up the reservior and see what is in there; oil or grease. I suspect it is going to be a thick grease like Lubriplate 105 which is sometimes used as a remedy for leaky seals on these old motors. It is highly water resistant and very sticky. I've seen a few comments out on the web about this approach to dealing with leaky seals which these old motors often develop with today's lubricants. Any thoughts about this method? I see some folks say it can work for quite a while. Alternatively, does anyone know where I can get a seal kit (and what that catalog # might be) and how hard is the fix? Would I need special tools etc?

 

[lindy46]

Re: '58 Johnson Seahorse 10 lower unit woes

Shouldn't be grease in the lower unit. Maybe previous owner excessively greased the prop shaft before putting prop on and that is what you're seeing.

 

[MushCreek]

Re: '58 Johnson Seahorse 10 lower unit woes

When you mix lower unit oil with water at high speed, what you get is what you described. My guess would be that some water leaked into the lower unit, and got whipped into a lather. Whenever I've drained a lower unit that leaked, that's what came out, and it's surprisingly thick. If that's the case, you need to put new seals in the lower unit.

 

[fiddlinmax]

Re: '58 Johnson Seahorse 10 lower unit woes

That's a big help, thanks. I open it up, check it out and add some new lube and see what it looks like after a little while.

 

[tmcalavy]

Re: '58 Johnson Seahorse 10 lower unit woes

Some folks do indeed replace the recommended gear lube with Lubriplate 105 white engine assembly grease...a modern equivalent to what was recommended in many pre WWII outboards that were direct drive (no F-N-R) and lacked modern rubber or synthetic seals. It does work as long as you drain the LU after each run...let the water out, and then top it off with Lubriplate again. If the gunk you see is the consistency of syrup and the color of peanut butter, it probably isn't Lubriplate...unless it is really ancient and past its useful life. As for a seal kit, check Laing's, Twin City Outboard or Engine, Blade & Prop...they're all on the web...if the Iboats mall doesn't carry it. The prop shaft seal isn't hard to change, but the drive shaft seal is often a different/difficult matter. As already noted, regular LU lube emulsified with water will be the color and consistency of a vanilla milkshake. Now, if you're real lucky and you do have a water intrusion problem...simply changing the o-rings/washers on the drain and vent screws will cure the problem. Hope so, but don't hold your breath...I'm never that lucky. Have a parts diagram at hand before you pull it apart to change the seals.