1964 9.5hp Johnson, Lower unit oil out of exhaust port

[T_J_B]

I ran out of room for my motors so I placed my 1964 9.5hp Johnson on the garage floor with the prop facing the ground. I came out the next day and noticed a good amount of lower unit lube on the garage floor. The only location I noticed it dripping from is the exhaust port?/screen just above the prop. I checked around the prop area but it appeared dry. Is there another bad seal that might contribute to this or is this a case of stupidity on my part?

Not sure if this is relevant, but I changed out the lower unit lube this winter and was suprised by the black color, metal flakes, and what seemed like water. I just got this motor so I assumed it was from the lack of maintenance from the previous own.

 

[Vic.S]

Re: 1964 9.5hp Johnson, Lower unit oil out of exhaust port

Perfectly normal and acceptable to lay the motor down as you did.

The oil leaking coupled with the water you found in the gearcase indicates a leaking seal. ... You are sure it was gear oil and not just unburnt oil from the fuel?

The drive shaft seal is the most likely culprit but a bad seal around the shift rod could also give rise to the same symptoms. It may well be worthwhile also changing the seal around the prop shaft in the gearcase head

Exploded diagrams in the parts catalog will identify these seals.

If you drop the gearcase to replace the seals overhaul the pump while you have it off.

Metal flakes in the oil are not good! Nor was the black colour of the oil.
If all is well gear case oil should come out clear and bright and no more than just a shade darker than it was when new.

Read THIS ITEM from the Engine FAQs board.

 

[ENSIGN]

Re: 1964 9.5hp Johnson, Lower unit oil out of exhaust port

Pressure test the gearcase and you'll know for sure,the water pump is also a great idea

 

[T_J_B]

Re: 1964 9.5hp Johnson, Lower unit oil out of exhaust port

I am sure it was lower unit lube because of the light carmel color. Is there an easy way to pressure test the lower gearcase? If there is a seal out what adhesive do you recommend if any?

 

[T_J_B]

Re: 1964 9.5hp Johnson, Lower unit oil out of exhaust port

It looks like the seal around the shift rod is the problem. I am sure I know the answer already but is there a way to replace that shift rod seal without exposing the propeller shaft and corresponding gaskets, seals, and "O" rings in the process?

I did drain the oil to see if water was present and surprisingly none was to be found. I recently found out from the previous owner that the oil could have been black because it never was changed in 40 some years.

 

[ENSIGN]

Re: 1964 9.5hp Johnson, Lower unit oil out of exhaust port

I'm a mercury/mercruser tech and I'm not exactly sure how to safely remove your shift shaft without the manuel,I do know the shaft has to be a certain lenght and is adjustable on some models.A factory service is your best bet before taking things apart.You can drain and apply 15 psi. of air pressure to the drive and put some soapy water on the seals and look for bubbles.Turn and try to wiggle the shafts when doing this.Good luck,Ted

 

[ezeke]

Re: 1964 9.5hp Johnson, Lower unit oil out of exhaust port

You will need to remove the lower shift rod to replace the o-ring seal; to do that, you must disassemble the gearcase.

You will need to purchase the correct seal kit: http://www.iboats.com/mall/partfind...&gd_poid=110557&gd_row=6&**********=650387270
The task will go better if you have a factory service manual.

 

[T_J_B]

Re: 1964 9.5hp Johnson, Lower unit oil out of exhaust port

Thanks..... that was the response I wasn't hoping for but expected.

Thanks ezeke for the 9.5hp seal kit link, what a time saver.