Lower Unit question

[Dale-Arizona]

Hi all,
New here. Looks like a great forum. I recently bought an older 30hp 2 stroke 3 cylinder. Its a 1989 30ELF motor.

I took it to the lake yesterday and it ran great! However the gear shift would pop out of reverse, probably just an adjustment?

Anyway to my question. I got home from the lake and decided to clean the motor real good. It had a quit a bit of grease and oil inside it. I very carefully cleaned it all with my pressure washer. (looks great now)

According to the previous owner, supposedly the lower unit was serviced within the last year. But I decided to drain it and take a look at the oil and it was a green milky color.

Question 1) Could i have caused this by pressure washing the motor? Or do you think it has a bad seal somewhere and its from running it at the lake?

Question 2) What kind of oil should I put in there? 75w-90?

I'm thinking about refilling it and taking it to the lake to run it a bit, then drain and check again for water.

Any comments,
Thanks so much in advance.

Dale - AZ

[99yam40]

it is a sealed unit, if there is water in it it has a seal problem.
use a marine lower unit oil/ gear lub available at all outboard dealers or big discount stores

[Dale-Arizona]

it is a sealed unit, if there is water in it it has a seal problem.
use a marine lower unit oil/ gear lub available at all outboard dealers or big discount stores

Thanks 99yam40. Yea, I guess I should try to find out if there is a bad seal.

Is re-sealing a lower unit a job that an average mechanically inclined person can do or are there special tools involved?

Thanks again,
Dale

[99yam40]

depends on which seal, prop shaft seal may need to pull carrier to change seal.
a Yamaha service manual is a must have if you plan on working on it yourself

[robert graham]

Lower unit leaks can be from Drain/Fill plug washers/seals bad, warn out shifter shaft seal, or drive shaft seal, or prop shaft seal. Check/Replace those Drain/Fill washers/seals first, drain and refill with fresh oil, run it in the river and re-check...you may be O.K.

[robert graham]

One other item, probably better not to use a pressure washer on an outboard motor...too many seals, bearings and places you don't want to force water into and blow lubricant out of....just a garden hose and mild detergent.

[Dale-Arizona]

99Yam40 & Robert,
Thank you guys very much for the info. It's helpful. I have been searching all over the net for a good service manual that will cover my 1989 30ELF motor but I have not been able to find one. Any suggestions? I did download a manual for $15 that covers Yamaha 2hp to 225hp, but I don't think its a very detailed manual and not sure it will be that useful. I can't even find anywhere in this manual that I downloaded, that tells me how much oil the lower unit holds.

I looked at the parts diagram on "boat.net" and I see a "shift rod boot" but I don't see a "shifter shaft seal"? I'm I just missing it?

Also, Robert, I think your right. It was probably not a great idea to use the pressure washer . I wont do that again.!

Thanks,
Dale

[Dale-Arizona]

Hi all,
Well I'm still baffled! I pulled the lower unit off and pressure tested it. I didn't find any leaks until I moved the shifter rod then I had a small one. I replaced the shiter rod boot/seal and the bracket that holds it down. Pressure tested the lower unit again. No leaks

To pressure test, I'm pressurizing it through the upper oil "Level" hole. I'm using 10psi.

Today I put in new oil (Yamalube lower gearcase oil) and went to the lake. Motored around for less than 2 hours, (tried a little fishing but no luck there either).

After I got home I drained the oil just to look at it. Much to my surprise it was milky again???? I expected it to look exactly like it did when I put it in.!

Take a look at my "before" and "after" picture.

So, am I expecting to much? is this normal for oil to look like this? Could it be air mixed in the oil? It doesn't seem to settle out? No "Clear" water came out when I pulled the drain plug? Is it possible that what I'm seeing is not water?

For you do-it-yourselfers, does you oil come out looking normal when you drain it?

But dang this motor runs nice!!

The good news is its now shifting fine. I think whoever serviced it last time didn't have the lower end and gear shifter in neutral when they assembled it so it was off and didn't stay in reverse.

Thanks Dale

[axolotl98]

Dont have any doubts.
There is water in your gear box oil.
You need to find the leaky gasket/oring and replace it