Johnson 8hp 1995

[Supersportster]

Hey all

I have a decent leak of gear oil coming out from where the lower unit meets the mid section..

I'm pretty sure it's the drive shaft seal.. My question is , is there anything special I need to know about changing it?

I've done the impeller.. Is it as simple as pulling everything back apart and pulling the drive shaft up and out? Or will I have to diss assemble the whole lower unit!??

 

[Bosunsmate]

Re: Johnson 8hp 1995

Its shoiuldnt be too hard.
I havent done one on that motor but it looks like you need to drop it again like you a doing the impellor, then also undo and lift up the cover that the impeller sits on.
Two lipped seals under there that you should be able to pry up, just be careful to not drop any bits into the bearings below.
Replace the gasket under the cover too

 

[Bosunsmate]

Re: Johnson 8hp 1995

You may as well do the o-ring for the shift rod while you have that cover off, its only an extra dollar or two.

 

[Supersportster]

Re: Johnson 8hp 1995

Thanks guys! Good point on not dropping anything down in there,

And I did order the shift rod seal!

So when the cover is off, the drive shaft will just pull out of the lower unit?

 

[Vic.S]

Re: Johnson 8hp 1995

Yes, or lift it out with the cover. Its only splined into the pinion. No retaining nut, pin or clip

Look at the exploded diagram on the parts website BRP -- Parts Catalogs

Note the two selals are fitted back to back

Take care when refitting the shaft not to damage the lips on the new seals.

Be sure the impeller drive pin is in place when refitting the impeller.

 

[Supersportster]

Re: Johnson 8hp 1995

Hey Vic, thanks for the info!

I got it all apart last night, I attached a couple pictures of what I found..

I didn't put it back together, because I wanted to double check how those seals go in. It is hard to see from the parts diagram.

When you say back to back, I put one facing down, with the flat metal outside facing up, then put the other one against it, with the little o ring facing up?

Thanks again!

 

[Supersportster]

Re: Johnson 8hp 1995

The seals that I took out, looked new, and so did all the gaskets. I was told when I got the motor a couple years ago, by the previous owner, that he had done all the gaskets and seals on the lower unit... But as you can see, it was leaking pretty good... I am thinking he might have had those seals in the wrong way?

 

[Vic.S]

Re: Johnson 8hp 1995

Hey Vic, thanks for the info!

I got it all apart last night, I attached a couple pictures of what I found..

I didn't put it back together, because I wanted to double check how those seals go in. It is hard to see from the parts diagram.

When you say back to back, I put one facing down, with the flat metal outside facing up, then put the other one against it, with the little o ring facing up?

Thanks again!

That sounds right

If you go to the parts diagram of the gearcase on the official parts website BRP -- Parts Catalogs and zoom in several times you will see how they go.

The bottom one has the side with the spring facing down and the upper one has it facing upwards. The bottom one keeps the oil in and the top one keeps the water out.

 

[the machinist]

Re: Johnson 8hp 1995

Not sure about that motor, but most older motors in that size for the front cavity below the water pump, do have a drain hole in the lower outer front side. This drains out any water or accumulated unburned fuel oil many times caused by a lot of trolling & the motor not getting warm enough to completely burn this oil. That color & consistancy of the oil seen in your photo is consistant with that problem.

If that is the case, there may not have been anything wrong with your seals, just that the drain hole was plugged.

 

[Vic.S]

Re: Johnson 8hp 1995

In your second picture you can see a little drain slot close to the front of the top face of the gearcase

also where the screwdriver is pointing in this picture ( Actually a Yachtwin hence the exhaust outlet in the extension and the second AV plate)

Another one on the other side but no other drain holes.

 

[Supersportster]

Re: Johnson 8hp 1995

Thanks guys! I think your right.

I used it ALOT for trolling this year, and everything looked OK when I took it apart...

I'll have a good look at the drain when I get home...make sure its not clogged

 

[Supersportster]

Re: Johnson 8hp 1995

do you mean that little slot that's on the right side of the right on the edge of that second pic?