1961 Johnson RDS-23 gearcase guts swap

[Griff805]

Hey guys-

Fixing up an old 1961 40HP Johnson sitting on a 64' Glasspar Lido and have gotten it running pretty well. What I've done so far:

Rebuilt carb
Rebuilt fuel pump
Replaced all fuel hoses
Replaced impeller
Replaced primer bulb and hoses

In the process of putting the lower unit back on- I broke the lower unit(gearcase?) housing because the metal is all pitted and weakened and didn't hold up too well to a rubber mallet. I've found a replacement lower unit housing and was hoping you guys could give me any tips or ideas on swapping the gears in the lower gearcase.

Is there anything in there that I should replace while I have it open? The prop seemed to be doing good in the water before I broke the housing.

I have a manual for the outboard, but it's not great and doesn't cover this area in depth. Does anyone know where I can find a good book/diagram for this outboard? Thanks guys-

 

[F_R]

Re: 1961 Johnson RDS-23 gearcase guts swap

So, are you swapping with a like year? Those things are pretty universal until you get up into the late '60s. Then the water intake was changed.

 

[Griff805]

Re: 1961 Johnson RDS-23 gearcase guts swap

I guess I should clarify a little bit. The only thing I need to do is swap housing. So, I am hoping I can just pull the gears out of my current gearcase and put them into the new housing which is from a 62 35HP Johnson. There are no gears in the new housing- it's empty.

 

[cougar1985]

Re: 1961 Johnson RDS-23 gearcase guts swap

I guess I should clarify a little bit. The only thing I need to do is swap housing. So, I am hoping I can just pull the gears out of my current gearcase and put them into the new housing which is from a 62 35HP Johnson. There are no gears in the new housing- it's empty.

omc never made a 62 35 hp .the last year was 1959 then they went to 40 hp.i think the guts from a 1959 35 and early 60,s 40 are the same .at least you got the same numbers for impeller,propshaft seal etc..

 

[Griff805]

Re: 1961 Johnson RDS-23 gearcase guts swap

omc never made a 62 35 hp .the last year was 1959 then they went to 40 hp.i think the guts from a 1959 35 and early 60,s 40 are the same .at least you got the same numbers for impeller,propshaft seal etc..

Oh- makes sense. Well, the lower unit looks exactly like the one I have on my RDS-23 and I am hoping/assuming they didn't change the housing internally for some reason.

 

[F_R]

Re: 1961 Johnson RDS-23 gearcase guts swap

Should be no problem going from 1959 to 1961 that I am aware of. In 1963 the pinion gear and drive shaft was changed and no longer has the drive shaft support strap. There probably is a way to work around that with a bit of drilling and tapping. And as I already said, in the late '60s the water system was changed and requires a different pump housing and water tubes.

Without knowing EXACTLY what you are proposing to put on there, that is the best answer I can give.

 

[Griff805]

Re: 1961 Johnson RDS-23 gearcase guts swap

Well, say that everything is compatible- What would be your guys' tips and suggestions on how to swap the gears and all the components inside to the new housing? Anything that I should do to speed things up, as well as make it easier?

Thanks for all the info so far. I'll post some pics of the new housing when it gets here and compare to the old one.

 

[Griff805]

Re: 1961 Johnson RDS-23 gearcase guts swap

Looks like the housing is from a later 60's model, as the locations for the water lines are quite different.

I'll post some pics up in a few minutes, but would anyone know of the simplest solution to accomplish the swap? Is this the only difference I need to be aware of? I sure hope so...

I have not been able to remove the screws that hold the gearcase together on the older unit yet, so I cannot compare for myself just yet. I'm wondering what I'll have to do to get those things out, seems like they welded themselves to the housing.

 

[F_R]

Re: 1961 Johnson RDS-23 gearcase guts swap

Anybody working on those things needs a hand impact screwdriver. The blade rotates a bit when you smack the end with a hammer. A must-have for working on outboards. Sears has them. So do the major tool mfrs. And even Harbor Freight, though theirs is sort of an el-cheapo. I've had my Snap-on for over 50 years, half of it in daily commercial use.

EDIT: Waiting on the pictures. I was afraid you would buy the wrong one. Actually, there were two changes to the water tubes, one 1968-ish, then again in 1970-ish. To make it even worse, there was a major change after that one. When I see the pictures, I can give better info.

 

[Griff805]

Re: 1961 Johnson RDS-23 gearcase guts swap

Uploading pics now- taking a while since i'm out in the middle of nowhere Alabama. As you'll see in the pics- i've also got a stuck driveshaft to take care of...

Should I go ahead and replace those screws with hex head bolts? Where would be the best place to find some stainless steel bolts with that thread pattern on them?

 

[Griff805]

Re: 1961 Johnson RDS-23 gearcase guts swap

Pics are still uploading- they will all appear correctly when uploading is completed.---------------------------


Pics of old housing from 1961 RDS-23 40HP Johnson:

 

[Griff805]

Re: 1961 Johnson RDS-23 gearcase guts swap

Pics of new housing from not-sure-what year Johnson, seller stated 62' 35HP, which as stated above, is not possible:

 

[Griff805]

Re: 1961 Johnson RDS-23 gearcase guts swap

As you can see, the water lines that the pump is supposed to pull from are in completely different places. Since the pump housing bolt locations are exactly the same, I am hoping I can just use a pump from the model that would fit the new housing... I don't see why that shouldn't work.

 

[Griff805]

Re: 1961 Johnson RDS-23 gearcase guts swap

I found that it looks to be a housing for a 69-70' 40HP motor. According to the part diagrams, the only differences seem to be that support strap you mentioned and the piping. However, it looks like the screw locations for the supports are still there- which means that shouldn't be an issue as far as I can tell. Won't know till I can get the other one apart.

Anyone know where I can get some water tubes from a 69-70' 40HP Johnson?

What do you think F_R- am I correct in my guessing?

 

[F_R]

Re: 1961 Johnson RDS-23 gearcase guts swap

Wow, what a salty dog!! Just when I thought I'd seen them all.

I think you are correct, it is a 1969-70 gearcase, and should work if you obtain the correct water tubes and pump parts. As far as I know, that is. I've never personally done the actual swap.

Have you looked for the parts on http://shop2.evinrude.com/ ?

 

[Griff805]

Re: 1961 Johnson RDS-23 gearcase guts swap

The boat was given to me recently and it's been sitting out of the water on a boat lift at a lake in the middle of Alabama. It's been in the same boat house for about 40 years, so I'm not sure why the bottom end is all chewed up like that..

You can see the rest of the motor looks fine- sitting on the end of a 1964 Glasspar Lido Clubsport I believe.

This will give you a shot of the Glasspar- When my brother and I took it out for a spin, before I broke the thing..

Anyway- I have looked at the evinrude parts place and they do have the parts, but I'm not really wanting to spend all that much if I don't have to. I'm kind of at that line where I need to decide if it is worth it or not. Anyone know how to get a good discount here at iboats?

 

[Griff805]

Re: 1961 Johnson RDS-23 gearcase guts swap

Or better yet, does anyone know where I can find an unwanted 1969 40HP Johnson lower unit?

 

[Force 120]

Re: 1961 Johnson RDS-23 gearcase guts swap

I have 1960 40 Hp Johnson, model# RDS-22 lower unit. I believe it is identical to your.

 

[Griff805]

Re: 1961 Johnson RDS-23 gearcase guts swap

Well, I am unable to remove any of the bolts in the gearcase housing. They must have fused somehow with the housing. I have tried impact screwdrivers and heat- they don't budge. Since the housing was weak I was able to remove a lot of the lower part of the gearcase housing. But I guess i'll just have to take a metal grinder to cut through the bolts to remove them or drill them out. Wish there weren't so many of them.

 

[Griff805]

Re: 1961 Johnson RDS-23 gearcase guts swap

Update--

Finally got the motor up and running pretty good- Ran about 5 gallons of gas through the thing in 2 hour trip today.

Ended up finding a donor motor for $50 that had a good set of gears, housing and water pump. I took it all and rebuilt the lower end with the best parts from each motor. Had a local mechanic swing by to make sure the gears were put together correctly- Didn't want to ruin the whole thing.

Driveshaft was stuck in the powerhead, but after a ton of whacking and hammering and cursing- it finally flew out with a final strike in frustration. Then replaced one of the water grommets and put everything back together. It went together relatively easily and it started right up after getting some gas in it.

Took it for a couple hours around the lake today and everything felt great- Engine sounds strong and the acceleration was strong and consistent. Didn't think I was going to get this thing back together, but I finally did and I am grateful to all the guys here to offered some advice and info- Good luck to you other guys-