9.9 seal problem

[daryl0815]

I have a 1979 johnson 9.9 that was slowly leaking lower unit oil from around the prop, only a very small amount, and it stopped after a couple of days, there is still lots of oil in the lower unit.

 

I noticed it after the last time that I parked the boat/motor, and noticed a small drip from the bottom of the prop onto the driveway.

 

There isnt much oil that leaked out, it was dark, and I havent drained the lower unit yet, but it isnt leaking anymore.

 

I am guessing that it is the prop seal that has failed, or is failing slowly (it is older than I am!), but I am not sure whether it is that or not, it just seemed like the most logical explaination.

 

I was hoping that one of the board members might have some insight into the issue, or experience with a similar situation, I have next to no experience when it comes to outbard repairs.

 

I was wondering if the prop seal can be replaced without removing the lower unit?, or if someone thinks it might think that it might be a different seal that is leaking?

 

Any help or advice would be greatly appreciated!

[Fisherman]

Before you start, 2 questions, 1. are you sure it's the prop seal, by removing the prop from the shaft and actually seeing oil at the shaft seal?

2. Does the oil have the distinct smell of hypoid oil and is it thick or is it unburnt 2 stroke oil coming out of the exhaust by the interior of the prop?

Edited September 22, 2010 by Fisherman

[daryl0815]

Before you start, 2 questions, 1. are you sure it's the prop seal, by removing the prop from the shaft and actually seeing oil at the shaft seal?

2. Does the oil have the distinct smell of hypoid oil and is it thick or is it unburnt 2 stroke oil coming out of the exhaust by the interior of the prop?

 

 

I did remove the prop, and I couldnt really tell where the oil was leaking from, it did look to be coming from in around the propshaft and dripping onto the lower wall of the housing.

 

I am almost 100% that it is lower unit gear oil, it didnt have a distinct smell (there was so little of it) and also, on my motor I beleive that the exhaust comes from 2 holes at the rear of the shaft and not from around the prop, but I could be wrong about that.

 

I have never had an issue of unburnt 2 cycle oil dripping before

Edited September 22, 2010 by daryl0815

[Fisherman]

I did some digging and found a link for you. From the picture and description, part of the exhaust goes down the leg of the motor, into a pipe and exits through the prop which has cut outs on each side close to the center. That's where it can become oily and people think it's a seal leak. Lower unit oil smells like even a very small amount, it's unmistakable. 2 stroke on the other hand can smell a bit "gassy" from being mixed. There's a whole breakdown of info at this site, I just copied the lower unit info. Here's your link: http://www.sschapterpsa.com/ramblings/Lower_unit.htm

 

Very important: Another point I found was to NOT remove the middle Phillips screw on the right hand side of the lower unit, if you do, you will have a beetch of a time trying to shift gears, this screw holds the internal shift pivot mechanism.

Edited September 22, 2010 by Fisherman

[HTHM]

If you take the upper screw out of the lower unit, observe the fluid (oil) that comes out. If it is a milky colour, you may probably need to redo the seals in the lower unit. If not, then Fisherman is probably correct in his assement.

[daryl0815]

Thanks very much for the info Fisherman and HTHM

 

I really appreciate it, Hopefully it isnt the seal, and it is just 2 cycle oil, I am going to go and check it out this afternoon! (the boat isnt at my house)

 

I have been nervous to take it out on the water because I dont want to make it worse, but if it just oil, maybe my motor is just running a little rich, or I mixed the gas a little rich. Musky season is here and I want to try to get out and get a big one!