Water mixed in lower unit oil.

[FasterE]

Good morning.

My Late 80's (I think it's an 87, maybe 89) 70hp Tohatsu lower unit oil looks like pancake batter.

I've awakened it from a 5 year sleep. It is running great otherwise.

I changed the lower unit oil (it looked like pancake batter), ran the engine in the back yard (in gear) at a low RPM for about 10 minutes (with the water attached). The next day, I ran it again for 10 minutes. I checked the oil and pancake batter again.

I'm guessing water pump seals. Admittedly though, I don't know what I'm looking at.

Is that a good place to start? You opinions please..


EW

 

[pvanv]

Re: Water mixed in lower unit oil.

Probably driveshaft seal. Located just below the water pump. In our shop, we wopuld replace all seals (not expensive items), including the often-overlooked shift rod o-rings.

 

[FasterE]

Re: Water mixed in lower unit oil.

Mr. Paul,

A couple questions please:

1) Can all necessary seals to correctly complete this job be purchased online? If yes, and if it's not too much trouble, can you recommend a vendor?

2) Are special tools required, i.e., is this something I can do myself with common tools and without a shop manual?

Thank you.

Errol

 

[pvanv]

Re: Water mixed in lower unit oil.

Any Tohatsu/Nissan dealer can supply the parts, even me. Remember that year of manufacture is unimportant, but precise model is.

No special tools are required, but an o-ring pick is handy when doing the shift rod o-rings. While everything is apart, that's the time to consider a water pump kit. No additional labor, nominal parts cost.

A Factory service manual (not the aftermarket woodstove tinder things) is always a good idea. Depending on your exact model, it's possible that the only source for a Factory service manual may be internetoutboards. See http://forums.iboats.com/showthread.php?t=395190

 

[FasterE]

Re: Water mixed in lower unit oil.

Thank you. I got it from here. Probably take it down this week, weather permitting.

Speaking of weather, we probably got a good foot of rain in the last 24 hours here in southern Louisiana.

But weather is really the least of my worries; My real concern is to get the darn thing sealed up and a fish in the boat before the authorities close the waterways due to oil sludge.

Errol

 

[FasterE]

Re: Water mixed in lower unit oil.

Paul, et al.

Ok, I got the shaft seal and o-ring from the local dealer. Took Jess 5 days to get the parts. The old shaft seal (outer: plastic over metal - inner: neoprene? over springs) was a Bi@#$ to get out of the housing. But after an hour of prying, being careful not to gouge the seal seat, it's out.

Also, the seat showed faint signs of corrosion. I gently scraped it out with a thin knife blade, and will probably finish off the cleaning with a soft, brass wire brush.

Question: Before pressing the new seal into the housing, should I prep it with any kind of special gasket maker? I'd probably just ligtly coat it with some lithium grease and get on with it.

Thoughts?

EW

 

[pvanv]

Re: Water mixed in lower unit oil.

"Before pressing the new seal into the housing, should I prep it with any kind of special gasket maker?"

Nope. Just press it in, using the usual mechanic's techniques to avoid wrecking it. It's a press fit, so shouldn't leak.

 

[FasterE]

Re: Water mixed in lower unit oil.

Seal pressed in without much trouble. I sandwiched the seal & seat between two pieces of wood and slowly squeezed with a C clamp.

It's all back together and passed initial testing. No water in the tranny oil this time after a 15 min run, low RPM in gear w/ the engine flush muffs. I'll be fully relieved when I get it out in the open water and back with no water intrusion.

Will keep my eye on it.

Thanks for the support.

EW