Lower Housing Cracked 1957 Big Twin

[danblue]

Is the "gear case housing" the skeg/fin and the housing unit just above the skeg/fin? So perhaps if my existing gears are good, I just find an empty used "gear case housing" and install my existing gear case into this new housing.

[danblue]

OK, I spoke to my outboard mechanic and told him everything. He suggested that I check the lower unit oil of my 1956??/1957?? Johnson Seahorse 35hp which I keep in my basement on a stand. He said if oil runs out, then this lower is THE candidate for an easy replacement of my Evinrude big twin 35hp lower. I just unbolt it, and bring him both the Johnson lower and the entire complete Evirude outboard.

Well, I drained the oil from the Seahorse 35hp, and just a tiny little bit of oily water dripped out, then a flood of honey colored, thick oil followed..it was still a steady small stream flowing 25 minutes after I opened it up, so I believe I’ll just take that lower unit off (the section I plan to remove attaches just above the propeller area, and it has a semicircle fin plate that runs all the way around, it’s bolted to the longer housing which runs all the way up to the main engine area of the motor) and have my mechanic do the work. He said it’s really easy, and they will inspect all the seals, drainage plugs, bearings, replace anything that needs replacing, and do a pressure test with soap and water, etc…and it should be good to go.

Question: I know for a fact that my Big Twin 35hp Evinrude is a 1957, but I am unsure of the exact year of my Seahorse…I want to make ABSOLUTELY sure my Seahorse lower is in fact a perfect replacement lower.

Thanks!

[hugh]

Hi Danblue, this is Hugh. I have not listed this lower unit on ebay so just contact me at 70hlong2020@gmail.com 775-443-7657 I went ahead and took it apart. I have photos for you just send me an email. It looks very good, no holes drilled in the cavitation plate.

[danblue]

Brilliant! Thank you Hugh.

I would much rather call to discuss if that is ok. I have some options, but would much rather have a 1957 Big Twin Evinrude 35hp lower replacement.

Thank you for these efforts!

Danny

[fleetwin]

Dan
Why do want to disable your other engine to get a gearcase for the engine you are working on? The 56 30hp gearcase will surely fit on your 57 35hp.
There are the seven bolts that secure the gearcase in place, but first you must disconnect the shift rod. The shift rod connector is hidden behind a small oval cover in the middle of the exhaust housing on the right side of the engine.

[Steve A W]

Dan
Here’s a couple parts breakdowns for the gear cases Your dealing with.

http://www.marineengine.com/parts/johns … =Gear+Case

http://www.marineengine.com/parts/vinta … 000001.htm

Good Luck with Your motor.

Steve A W

Member of the MOB chapter.
I live in Northwest Indiana

[danblue]

quote fleetwin:

Dan
Why do want to disable your other engine to get a gearcase for the engine you are working on? The 56 30hp gearcase will surely fit on your 57 35hp.
There are the seven bolts that secure the gearcase in place, but first you must disconnect the shift rod. The shift rod connector is hidden behind a small oval cover in the middle of the exhaust housing on the right side of the engine.

Hello Fleetwin,

I don’t know of any other option but to find an operable lower unite (gear case) and just replace the broken unit on my Evinrude. Simply unbolt the Johnson as an example, and bolt the Johnson onto the Evinrude Big Twin. (And have my mechanics test pressure, replace seals, etc. at the same time.)

As I have learned from the nice folks posting here, my tail fin piece that is cracked and the above housing are machined at the same time, so I need to just go ahead and replace the whole thing.

I’m working with a fellow that has a lower for a 1957 Evinrude Big Twin 35hp that would be an exact match for me, and apparently the gears are all in good working order and clean, etc..

I guess I just don’t understand exactly what other options I might have. If you could clarify, I would certainly appreciate.

Thanks!

[fleetwin]

Yes, I totally agree, replacing the complete gearcase is probably the simplest/most cost effective option. I just didn’t want you to take a gearcase off a good running engine, I’m glad another member has a gearcase for you.

[danblue]

Dan
Here’s a couple parts breakdowns for the gear cases Your dealing with.

http://www.marineengine.com/parts/johns … =Gear+Case

http://www.marineengine.com/parts/vinta … 000001.htm

Good Luck with Your motor.

Steve A W

Thank you for this Steve! The first link is exactly what I’m planning to replace…the complete unit as outlined in that blown up illistration…I have a couple of options, so I guess my mechanics will inspect whatever lower I bring to them, replace any worn parts, etc..then just bolt that puppy up to my Evinrude.

[danblue]

quote fleetwin:

Yes, I totally agree, replacing the complete gearcase is probably the simplest/most cost effective option. I just didn’t want you to take a gearcase off a good running engine, I’m glad another member has a gearcase for you.

Yes! If I can purchase a good operating gear case that matches my engine, I would much rather just go ahead and buy it and not take the Johnson apart.

I’ll keep you all posted and I appreciate your help!

Danny

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