Evinrude 55 1978 gearcase

[Mikko]

Hello,
I have owned Evinrude 55 1978 since 2013 and it's been working well. Now I first time decided to change the water pump impeller and after removing the gearcase I found that a lot of exhaust gases must have been leaked inside there (black soot). In the figure (arrow) it can be seen a leak even out from gearcase. I think it must be the exhaust tube seal, but I'd like to ask if someone has any experience of this. Another question concerns a small fracture reaching the threads of the oil hole (former owner obviously hit the rock?). There has been a small oil leak, but despite of that oil has remained fairly clear. Most likely there is nothing to do with this?

 

[Crosbyman]

imho the crack is a concern and may render the next " collision" more catastrophic . You can get it welded and polished to restore some solidity.
In th mean time keep checking the gear oil for contamination and adequate level.

as to black soot it kind of normal just make certain that upon reassembly you follow the procedure to possibly increase the sealing. For example on my ETEC they recommend a adhesive to secure the rubber adapter.



you may want to clean up the underside of the pump cavity that looks corroded or caked with deposits. Just apply/soak hot vinigar to loosen up the deposits and scrub//wire brush the stuff.

 

[saltchuckmatt]

Any friend with a tig welder can do this in minutes....at least the welding. Grind/polish yourself.

Bring beer.

If you want, and since it's off there is a few more seals you can replace. Inexpensive maintenance can help make sure the old girl can still parade around.

 

[Mikko]

Any friend with a tig welder can do this in minutes....at least the welding. Grind/polish yourself.

Bring beer.

If you want, and since it's off there is a few more seals you can replace. Inexpensive maintenance can help make sure the old girl can still parade around.

I think I can do it with this JBweld, but the problem is that the crack is probably in the threads of the drain plug and then I am not sure if the nylon plug gasket prevents the leak.

 

[Crosbyman]

imho the small crack surface area JB will cover will be visually ok by will not solidify the GC enough . you best best is to have it welded properly .
Up to you.

 

[tphoyt]

imho the small crack surface area JB will cover will be visually ok by will not solidify the GC enough . you best best is to have it welded properly .
Up to you.

I agree with that.
It’s likely just one bump away from a bigger problem. I would get er done sooner than later while you still have something to work with.
Best

 

[racerone]

Find a good used empty gearcase.----Swap everything over.

 

[Crosbyman]

certainly the best option..could even be cheaper than welding...around here anyway....and the thread crack will be past history !

 

[Mikko]

I'm not afraid that crack will increase at all (it's been there over ten years), the only concern is a small leak there (not increased at all during those years) and I think JBweld could help a bit in this problem.

 

[Crosbyman]

try to rinse away any oils ...

clear liquid Crazy glue could seep into the carck and seal it... won't solidify it much but it may seal it good.

btw if you want to harden crazy glue instantly just spray it with a small bottle mix of rubbing alchool with some diluted baking soda (1/4 tea spoon will do !) . Amazing ! no need for pricy Accelerators !! check Utubes

 

[Mikko]

I have two questions concerning this lower unit: how should the O-ring inside the shift rod cover be changed? Is it possible to remove the brass mid part (bushing?) ? Another question is about a small hole in the trim tab. Does the water flow assist someway the exhaust gases to get out through the propeller?

 

[racerone]

Use a sharp pointy tool.----Remove o-ring.-----Install the new o-ring.-----That hole may spray water into the exhaust for cooling.----Do not fuss over that hole.

 

[Mikko]

I found one youtube video which shows the entire process for lower unit seal replacements.

 

[Crosbyman]

may as well share the info for others ...

 

[saltchuckmatt]

This is the breakdown of your motor, if it separated they would show it that way.

 

[Faztbullet]

That hole in trim tab adds water to exhaust to cool prop hub

 

[Mikko]

may as well share the info for others ...

evinrude 55 shift rod seal replacement - Google Search

 

[Mikko]

This is the breakdown of your motor, if it separated they would show it that way.

Cover is like this

 

[racerone]

Simple job to replace the o-ring in there.-----But I have seen this presenter trying to hammer tapered dowel out of V-4 and a V-6 block.----Trying to POUND them out in the wrong direction.

 

[Mikko]

Simple job to replace the o-ring in there.-----But I have seen this presenter trying to hammer tapered dowel out of V-4 and a V-6 block.----Trying to POUND them out in the wrong direction.

... yes, the methods in the videos may easily cause damage and new problems . O-ring change seemed to be everything else but simple