1979 7.5 Gamefisher

[troutchaser-48]

I was given an old model 217585931. It does run.I found oil leaking from the exhaust hole. It looks as if the oil is coming from the short section of shift rod that goes into the lower unit.I checked the oil and it is milky. I believe I will have to dismantle the lower unit to replace the o ring and seal on the shift rod or am I wrong. Has any one done this before. I would imagine that I should replace all the lower unit seals once its apart? Does any one have a good lower unit thay may want to sell? Any help on this would be appreciated.

 

[Tom @ Buzzard Bluff]

Re: 1979 7.5 Gamefisher

<I was given an old model 217585931. It does run.I found oil leaking from the exhaust hole.>

Depends on your definition of 'exhaust hole'! People often mistake a normal condensation of waste engine oil and water that can seep out of the drainage holes of the exhaust leg for days as leaking lower unit gearbox oil.

<It looks as if the oil is coming from the short section of shift rod that goes into the lower unit.I checked the oil and it is milky. I believe I will have to dismantle the lower unit to replace the o ring and seal on the shift rod or am I wrong. Has any one done this before. I would imagine that I should replace all the lower unit seals once its apart? Does any one have a good lower unit thay may want to sell? Any help on this would be appreciated.>

The air-cooled Clintons & Eskas are often derided for many other perceived short-comings but their worst Achilles Heel was the cheap lower units they used. They used only bushings for bearings and the seals verged on a bad joke.
Once a seal started leaking (which they did soon compared to the 'high-priced spreads'!) the steadily decreasing supply of lube allowed the bushings to wear quickly. So----check the bearings in your lower unit. If both driveshaft and propshaft have no excess sloppiness than a COMPLETE reseal of the L/U should suffice.
ALWAYS have new L/U seals on hand and change them at the first hint of water intrusion-----and check often!

 

[Tommy Two Stroke]

Re: 1979 7.5 Gamefisher

<I was given an old model 217585931. It does run.I found oil leaking from the exhaust hole.>

Depends on your definition of 'exhaust hole'! People often mistake a normal condensation of waste engine oil and water that can seep out of the drainage holes of the exhaust leg for days as leaking lower unit gearbox oil.

<It looks as if the oil is coming from the short section of shift rod that goes into the lower unit.I checked the oil and it is milky. I believe I will have to dismantle the lower unit to replace the o ring and seal on the shift rod or am I wrong. Has any one done this before. I would imagine that I should replace all the lower unit seals once its apart? Does any one have a good lower unit thay may want to sell? Any help on this would be appreciated.>

The air-cooled Clintons & Eskas are often derided for many other perceived short-comings but their worst Achilles Heel was the cheap lower units they used. They used only bushings for bearings and the seals verged on a bad joke.
Once a seal started leaking (which they did soon compared to the 'high-priced spreads'!) the steadily decreasing supply of lube allowed the bushings to wear quickly. So----check the bearings in your lower unit. If both driveshaft and propshaft have no excess sloppiness than a COMPLETE reseal of the L/U should suffice.
ALWAYS have new L/U seals on hand and change them at the first hint of water intrusion-----and check often!

Tom, why do you say the seals Eska used "verged on a bad joke"? I've taken apart quite a few Eskas and OMC engines, and both use standard single lip oil seals - no real difference between either, and certainly state-of-the-art for the time these engines were made. Seals in general have improved in recent years - the fully rubber-encased seal I used in the lower crank seal repair described in another posting has the advantage of the rubber seal area being less likely to be ripped from the metal seal frame since it fully encases the frame. I think if this type of seal upgrade could be made to any engine of this vintage, that would be helpful.

 

[Tom @ Buzzard Bluff]

Re: 1979 7.5 Gamefisher

<Tom, why do you say the seals Eska used "verged on a bad joke"? I've taken apart quite a few Eskas and OMC engines, and both use standard single lip oil seals - no real difference between either, and certainly state-of-the-art for the time these engines were made.>

Like yourself my opinion is based on experience. The number of bad lower units that I've seen far exceeds any other problem. I suspect the quality of the seal they used was the problem. I currently have 3 Eskas on hand that run very well indeed but are awaiting lower units. I recently went thru an outboard junkyard looking for good lower units. Of the 20-30 Clintons & Eskas I inspected there wasn't a single L/U I was willing to gamble on.

Another example-----
I have an '86 model (last year of production) 7 1/2 Eska with virtually no time on it. It's not even what I consider as 'broken-in' yet. It's awaiting new L/U seals when it gets to the top of the list.

By contrast I just rehabbed a '58 Evinrude Lightwin. Took it out of the testank after declaring it once more ready for service yesterday and changed the L/U lube. Didn't need to as it was as dry as a bone.

I'm a big believer in paying attention to the evidence. And the evidence from my perspective is that the Eska/Clinton seals were a POS.

 

[Tommy Two Stroke]

Re: 1979 7.5 Gamefisher

<Tom, why do you say the seals Eska used "verged on a bad joke"? I've taken apart quite a few Eskas and OMC engines, and both use standard single lip oil seals - no real difference between either, and certainly state-of-the-art for the time these engines were made.>

Like yourself my opinion is based on experience. The number of bad lower units that I've seen far exceeds any other problem. I suspect the quality of the seal they used was the problem. I currently have 3 Eskas on hand that run very well indeed but are awaiting lower units. I recently went thru an outboard junkyard looking for good lower units. Of the 20-30 Clintons & Eskas I inspected there wasn't a single L/U I was willing to gamble on.

Another example-----
I have an '86 model (last year of production) 7 1/2 Eska with virtually no time on it. It's not even what I consider as 'broken-in' yet. It's awaiting new L/U seals when it gets to the top of the list.

By contrast I just rehabbed a '58 Evinrude Lightwin. Took it out of the testank after declaring it once more ready for service yesterday and changed the L/U lube. Didn't need to as it was as dry as a bone.

I'm a big believer in paying attention to the evidence. And the evidence from my perspective is that the Eska/Clinton seals were a POS.

Interesting observation. You make a good point that the quality of the actual sealing material wasn't very good back then. Nitrile seals seem to have come into vogue for general purpose sealing in the last 20+ years - I've never been sure of exactly what material the older (1960's, 1970's) seals were made of.