1990 9.9 Evinrude Lower Seals

[mikewoller]

Recently I hooked my motor up on the garden hose and ran it. To Make a long story short, after putting it back in the garage, the next am there was gear lube leaking out from the prop onto the floor. I assume the seals are shot all of a sudden??? Is this a simple fix that I could do myself? If so, does anyone know the step by step procedure in replacing these seals? Could these seals have gone bad from running the motor on the garden hose ears? Thanks for any help!

 

[Rick.]

Re: 1990 9.9 Evinrude Lower Seals

You're probably OK. It is normal to see unburned gas/oil leech out of the prop center and the leg drain hole after running the motor. If your oil leakage is dark grey to medium brown you have nothing to be concerned about. Rick.

 

[mikewoller]

Re: 1990 9.9 Evinrude Lower Seals

its actually a creamy looking color. I'm positive it's gear lube, there was a puddle the diameter of a softball on the floor. Seals bad you think??

 

[Mas]

Re: 1990 9.9 Evinrude Lower Seals

Check you LU lube level and color by draining a bit from the lower plug...if it is milky, you do have a bad seal.

MAS

 

[mikewoller]

Re: 1990 9.9 Evinrude Lower Seals

when i drained the lube it looked fine. A Few drops on the floor wouldn't really excite me too much , but it was literatly a puddle the size of a softball?? I have drained the rest of the gear lube? Do I replace seals, or fill it back up n run it? Is there a possibility i could of had it too full to begin with, and the excess ran out??

 

[Rick.]

Re: 1990 9.9 Evinrude Lower Seals

mikewoller: Your confusing me a little. You say the gear lube you drained looked fine. I'm not sure if fine means the same color as what you found on the floor or what. I doubt the gear case was overfilled but anything is possible I guess. If you had a leak that would drain a lot out it wouldn't stop when it hit the correct level. It would continue to drain until there was none left I would think. That lube never gets hot, probably never even warm considering the environment it operates in so there wouldn't be thermal expansion causing it to push out a seal and then stop. The color you describe I have not seen but I'm still thinking it is just exhaust oil. Rick.

 

[mikewoller]

Re: 1990 9.9 Evinrude Lower Seals

Rick,
Sorry for confusing you!! The oil I drained WAS a different color than the oil that was on the floor. The oil I drained looked good/pretty clear. The oil coming out the back of the prop was a tanish/light brown color. The reason why I was running it on the hose with the ears, is because the low speed setting was WAY OFF!! I ran it on the hose for probably 7-8 mins until I got the setting correct . (It was only turned out 1/2 turn from seat, and would not idle correctly). If I fill it back up with new fluid (and not run it) and the seal was bad, would it leak out on the floor? Would that tell me weather it is exhaust oil or a seal bad?? Hope I cleared things up!! I appreciate all of your help!

 

[Rick.]

Re: 1990 9.9 Evinrude Lower Seals

Yes go ahead and refill it. You should use new plug seals ( little nylon washers). Once full, put the top plug in first and that will stop it from draining out the bottom while your putting the bottom plug in. That does seem like a lot of oil for such a short run but with the muffs on it you might have cleared a passage that was blocked so you got mote than the usual amount. Running it on the muffs should not cause any seals to leak. Good luck. Rick.

 

[mikewoller]

Re: 1990 9.9 Evinrude Lower Seals

bad bad bad.....
re-filled it w new gear lube. Brought it back outside hooked it back up to the hose, and after about 2 mins of running i looked at the prop, and the inside was COVERED in milky gear lube, to the point is was a steady drip from the inside of the prop to the ground!!!! I brought it in, drained it again (odd thing is that when i pulled the drain plugs out CLEAN NEW oil came out,not milky at all!!!!) , pulled it apart, and pulled the seals out. After it was drained, i pulled the shaft and the gear that rides on the shaft, out. Here are my findings......2 small ball bearings 3/16 outside width, and a small stout spring measuring 5/8 of an inch long, and 3/16 thick!! What the heck is this!! Please tell me these have something to do with the 2 seals i pulled!!!

 

[Mas]

Re: 1990 9.9 Evinrude Lower Seals

Sounds like you removed the prop shaft detent balls and spring. Before you continue...get the shop manual to walk you through the process.

MAS

 

[mikewoller]

Re: 1990 9.9 Evinrude Lower Seals

I got them back in the shaft, along with the spring!!! WHEW....that scared me!!! I have most of it put back together, I will run to the marina mon morning and pick up 2 new seals, and an O ring. Hopefully the seals and the new O ring cure my problem?? I did notice when taking the O ring off that is had a small slice almost half way through it.

 

[Mas]

Re: 1990 9.9 Evinrude Lower Seals

I'm assuming that you have "thru hub" exhaust.

Make sure you use gasket sealing compounds to the outer edges of the seals...making sure none contacts the seal lips. The seals should be installed back to back. Install the seals so the "lips" DO NOT face each other. The first lip faces to the interior of the LU, while the second faces the prop. Also, use grease on the o-ring.

You also have a a pair of seals on the drive shaft that may also be the cause an oil leak.

MAS

 

[mikewoller]

Re: 1990 9.9 Evinrude Lower Seals

wouldn't it have to be a seal on the prop shaft or the rubber O ring, for it to be leaking out the prop??

 

[Mas]

Re: 1990 9.9 Evinrude Lower Seals

Yes...if oil is leaking out while the motor is not running and vertical...especially in the amounts that you described.

Any sign of fishing line around the prop shaft when you pulled the prop off?

MAS

 

[mikewoller]

Re: 1990 9.9 Evinrude Lower Seals

no, brand new prop, no line anywhere. it didn't leak while just sitting, just when I started it up and put it in gear, and after 2 mins it was a MESS!!! It was caked on the inside of the prop, and dripping out. Weird thing is, when I opened the drain to drain the fluid, it came out just as new as when i put it in!!

 

[Mas]

Re: 1990 9.9 Evinrude Lower Seals

I would not expect the LU oil to get milky on muffs...just out on the water. It seems that only oil is getting out...not water in at this point.

MAS

 

[mikewoller]

Re: 1990 9.9 Evinrude Lower Seals

so, if you think only oil is getting out, and not water getting in, are you thinking its one of the lower seals or the O ring??? How could oil be getting out?? Im lost here!!

 

[Mas]

Re: 1990 9.9 Evinrude Lower Seals

There are two seals around the prop shaft installed back to back...one to prevent oil from getting out...the other to prevent water from getting in. Water has a lot more difficult time getting in unless the LU is totally submerged in water...not on muffs.

MAS

 

[Rick.]

Re: 1990 9.9 Evinrude Lower Seals

mikewoller: What a drag. Oh well you on your way with the repair anyway. Did you happen to pull the top plug and confirm your oil level had dropped after your short run? The best way to know what seals are leaking is to do a pressure and vacuum test on the gear case. Trouble is you have to have it all together for that. Having said that, I have never done one. When I've seen water in the gear case I just do them all. If your certain your leaking oil from the gear case then your probably right going after the seals your doing given your dripping out the prop. I hope your following a manual for this repair. Rick.


Edit: Here is a parts diagram for your motor and gear case if you don't already have one.
http://shop2.evinrude.com/ext/index.aspx?s1=388dda0bb6badbcdd10f6ac17c163f07

 

[OptsyEagle]

Re: 1990 9.9 Evinrude Lower Seals

The reason you are probably leaking oil out and not water in, is because the going theory is, that when a motor is running, the gear oil heats up, expands and creates an internal pressure that pushes the oil out of a bad seal (the oil is usually too thick just to flow out without any pressure).

It is only when the motor stops running and cools down that the contracting gear oil now creates a vacuum to suck the water in. If you are running on muffs or you pull it out of the barrel before the gear oil cools down completely, there is a good chance that no or very little water will enter the gear case, even with a bad seal.