Fitment Question for Gear Case Assembly 54 Fleetwin

[drifter]

Just completed a refurbish on a 1954 Fleetwin (model 7514) 7.5hp. All new lower unit seals, “O” rings, and gasket. Filled up the lower unit. Next morning noticed drips of oil. Upon a very close inspection I discovered a small vertical crack directly above the gear case head and bearing assembly. Under bright light I could actually see the oil seep out.
Off to the parts boxes and I did find an Evinrude gear case assembly, upper and lower from a 1957 Fisherman (5514) 5.5hp. After a lot of measurements and a bolt up, it all seems to fit my 54 Fleetwin.
Did some searching in my parts books and discovered the following: The 7514 (54 – 7.5hp) gear case assembly is p/n 376062 and the 57 (5514 – 5.5hp) gear case assembly is p/n 376775.
So the big question is, are theses gear case assemblies interchangeable?

Thanks again for all of your help.
Nick

[drifter]

Forgot to add …the gear case head and bearing assembly is the same p/n (376776) for both outboards.

[fleetwin]

I think the driveshaft and shift rods might be a slightly different height on the 55 and older versions of the 5.5 and 7.5 models when compared to the rubber mount midsection engines….
This is a great topic though, so I guess I will have to do some research…But, I don’t have access to 1955 parts books…

[crosbyman]

I have a nice 10 hp Golden jubilee oozing like that… tried hard but can’t locate the real.. slow leak so when I hit the cottage I will include some UV dye in the oil and use a UV lamp to find the drip point 🙁

and will try to do a pressure/vacum test

Joining AOMCI has priviledges 🙂

[frankr]

Hm-m–m-m-m, I just spent half an hour trying to figure out why the ’54 and ’57 gearcases have different part numbers. No answer yet. But I do remember when I did that several years ago, everything went well until I went to put the prop on. Wouldn’t clear the nose part. But it worked after I knocked some of the webbing out of the old prop. That’s all I remember.

[garry-in-michigan]

There were changes in the propeller and the prop shaft seal and bearing assembly to try to keep the nylon fishline away from the prop shaft seal. It really didn’t,t help much. but did complicate prop selection.

[fleetwin]

So the prop shafts and shift rods are the same?

[frankr]

fleetwin wrote:

So the prop shafts and shift rods are the same?

Don’t try to take this to the bank, but I Think the drive shaft and shift rod lengths changed with the introduction of rubber mounts. But the change was in the exhaust housing, not the empty gearcase. This opinion and $2 will get you a cup of coffee at the corner gas station..

[fleetwin]

Not to worry Frank, I won’t try to deposit your advice in the bank…So, I think you are saying that the height of the spring mount vs rubber mount midsection was slightly different, so the height of the driveshaft and shift rod had to change also….I kinda thought this was the case… Wish I had a 55 parts book to compare each piece against a 56 model with rubber mounts…
So, I’m guessing that the part numbers of the two empty gearcases is the same….Perhaps the older gear housing supercedes up to the 56 and newer rubber mount engines…

[frankr]

No the empty gearcase part numbers are not the same. Dunno why.

[Author]

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