1974 johnson

[whitepointer23]

I have a 1974 johnson 50 hp outboard with cable controlled hydraulic gearshift. I have heard dexron trans fluid is suitable for the gearbox . Wondering if anyone knows about this.

 

[powerabout]

never heard that but cant see it hurting
trouble with atf is it gets hot and expands and foams
We did run it in smaller engines when racing them for less drag.

 

[whitepointer23]

I read on the net that dexron is a good alternative to omc premium . The reason being that regular gear oil is to heavy to flow through the powershift pump galleries when cold. Makes sense in that respect.

 

[whitepointer23]

When you say smaller engines do you mean gearboxs on small racing outboards.

 

[powerabout]

When you say smaller engines do you mean gearboxs on small racing outboards.

any depending on the load, you wouldnt do it on a ski boat with a v6 and it will wear them out a bit faster as its not an extreme pressure oil like gear oil
2 cyl 50 with a club foot has plenty of gear size so not heavily loaded.

 

[whitepointer23]

Thanks again pb. I filled with dexron . I did a bit more reading and i definitely can't use gear oil. It is just to thick for the powershift hydraulic pump.

 

[sandhammaren05]

I have a 1974 johnson 50 hp outboard with cable controlled hydraulic gearshift. I have heard dexron trans fluid is suitable for the gearbox . Wondering if anyone knows about this.

The problems with electroshift were notorious. I have a dealer friend who gave up on them. However, I have a friend who raced a model in the late 1960s, he used and recommends automatic transmission fluid. Claims he never had a problem. The problem is to get the filter clean and keep it clean. That said, with a clean filter the exact fluid may not matter-OMC gearcase oil for that motor was pretty much like transmission fluid, according to my dealer friend.

 

[whitepointer23]

The problems with electroshift were notorious. I have a dealer friend who gave up on them. However, I have a friend who raced a model in the late 1960s, he used and recommends automatic transmission fluid. Claims he never had a problem. The problem is to get the filter clean and keep it clean. That said, with a clean filter the exact fluid may not matter-OMC gearcase oil for that motor was pretty much like transmission fluid, according to my dealer friend.

Thanks for the reply. The pre 1974 motors were electric shift hydraulic. The solenoids had to be perfectly clean or they would play up. Mine is the cable shift hydraulic which is more robust and reliable. I am running it on dextron 3 at the moment .

 

[powerabout]

funny how BRP have gone back to electric solenoids in the gearbox so they werent so bad afterall...

 

[whitepointer23]

funny how BRP have gone back to electric solenoids in the gearbox so they werent so bad afterall...

Thats interesting pb. Are etecs electronic control or still cable remotes.

 

[powerabout]

the g2 have finally gone electric and the gear box has solenoids in it to shift its on teh V6 not sure how far down the line that goes