1977 Johnson - Lower Unit - Parts required duing rebuild

[spencroy]

Hello Everyone.

1977 Johnson ? 115 - 115EL775 - Ranger Fish and Play

I noticed this weekend after a 12+hour fishing trip that there was oil leaking between my upper and lower unit:

Having been warned on this forum in the past of potential expensive repairs in the future if problems in the lower unit are left unchecked, I decided I better pull it apart and try to figure out what is going on.

I have two theories going in as the the cause:
- I have mixed the oil/gas to rich with oil (I have white smoke for example at startup pretty bad). I am theorizing the rich mix is causing oil in the exhaust, and this is somehow seeping out between upper and lower unit
- The Shift rod/caseing/filter etc is leaking

(am I off in left field?)

Drained oil
- while draining the oil a very small amount of water ? no metal
- oil was dark black

I followed the SELOC guide removed:
shift rod/caseing
lower shift rod and "assist solenoid"
prop to reverse gear (I will open another post about why I did that.. had another problem to solve while I was in here)

- No obvious water intrusion
- no corrosion
- forward/pinon are fine
- no obvious signs of oil on/in/around the shift rod caseing

I am now trying to get my shopping list together for the parts which will be required to rebuild.

Since I did not remove the forward gear assembly or driveshaft assembly my question is does this seem like a reasonable list?

Parts Required
Name Part Number price
Gasket, Shift Housing 18-0110 2.99
O-Ring, Shift Rod 18-7137 3.99
O-Ring , Bearing Housing 18-7127 2.99
Water Pump Repair
Kit w/Housing 18-3393 68.99
Sierra Solenoid 18-5808 17.99 (another post)

The water pump appears fine, but the first thing anyone on this form ever told me was replace the impeller. I am thinking the complete kit may be overkill?

Since I only removed the reverse gear, I am thinking the o ring behind (prop side) those retaining rings from hell, the gasket on the houseing, and that o ring on the shift rod are all I need to replace. Am I missing something?

Also, since I am in the lower unit anyway, is there something else I should replace/check/do to help eleminate possible leaks?

Any advice - suggestions would be appreciated.

 

[spencroy]

Re: 1977 Johnson - Lower Unit - Parts required duing rebuild

I found the root cause to be the gasket for the exhaust system:

sorry about the pic quality

I am adding a replacement gasket to my list.

However, if anyone reads this post (this one must be bad as no one has looked at it.. sorry about that) I am still curious if from the look of that exhaust if I am not mixing my oil/gas way to rich. To me the oil remaining in the exhaust shaft seems to be excessive, but having never seen the inside of a lower unit till now I am not sure if that is not just normal.

Any other suggestions before I start my rebuild would be appreciated.