Oil overflow from sterndrive reservoir

[wooolffy]

Hi fellow Maxum owners. I have a 1998 Maxum 2100sc. She is in great shape. I changed impeller and gaskets in fall and filled up with new sterndrive oil. Took her out for a 3 hour run. While anchored we noticed a drop of oil rising to surface and leaving a slick on water. This happened every 2 minutes or so. I checked reservoir oil level and it was reading smack on full. Returned to marina and docked. While closing her up I checked bilge and it was full of sterndrive oil. Tank was on minimum , what the heck? Is the oil that warm that it expanded that much, or am I taking in water and spitting out oil? Iam new to boating and Iam a hands on mechanic.

I am not sure what to do, pull boat and open lower drain and look for water, and if none found then what?
I'm sure you guys will help me with my dilemma . If I find water then it is pull unit and do seals. Cheers.

[mcoffey]

There is only 2 ways that I know of for outdrive oil to leak into the bilge area.
1) Oil reservior, hose or thru-hull fitting is leaking
2) Drive shaft seal is leaking

I had #2 happen to me last year, it sucks.
So first thing to do is fill it back up and check the reservior and hose all the way back to the transom. I found a mirror and some special yoga poses helped a lot here (a;long with flashlight). If you cannot find any leak at all, start looking at the backside of the motor. I found that I could see a drip of oil every so often land into the clean bilge area and when I started looking above that, I saw oil leaking off the transom bracket right behind the motor.

Now I needed a Gimbal bearing anyway so I decided to pull the leg. Once i popped the seal, the entire bellows let out all the oil it had been holding. So when it is the shaft seal, the only place it can leak is into the bellows and once it is full enough, it starts leaking into the bilge area. This is because the shaft is below the fill tube that the reservior is connected to. So it will keep filling the drive until all out.

Now if it does turn out to be the shaft seal, might as well replcae all bellows and Gimbal (if not recently done). Also take the outdrive to a trustworthy Marina and have them re-seal it for ya, and might as well replace the impeller since they need to crack it open.

Good luck and I hope it is just a simple hose or cracked reservior

[seapuppy]

yep..what mcoffy said....can't add anything else to that....

hope it's not serious but I'm afraid it does sound that way....

BOAT= Break Out Another Thousand!!

SP

[shrew]

Is the drive lube resevoir covered with oil as well? I've seen an air bubble sork it's way up after changing the drive lube oil. Now when I fill the drive, once it starts to show up at teh resevoir, i stop. Every time, if you wait long enough after you stop, you'll see the oil level in teh resevoir rising still. then the ait bubble works it's way out. Ive seen guys fill the drive and resevoir to full, then walk away as it starts to overflowthe resevoir. That could theoretically spill oil into the bilge. Once the air bubble(s) are worked out, you might see teh level drop again. This could also account for the level dropping. It wouldn't account for the oil leaking into the water, however.

When you changed to drive lube, did you use new drain and level screw washers? Did you use the old ones, or are there none on the drive lube drain and check screws at all? This could for a small oil leak in the water.

Just a couple of thoughts.

[wooolffy]

Originally Posted by shrew

Is the drive lube resevoir covered with oil as well? I've seen an air bubble sork it's way up after changing the drive lube oil. Now when I fill the drive, once it starts to show up at teh resevoir, i stop. Every time, if you wait long enough after you stop, you'll see the oil level in teh resevoir rising still. then the ait bubble works it's way out. Ive seen guys fill the drive and resevoir to full, then walk away as it starts to overflowthe resevoir. That could theoretically spill oil into the bilge. Once the air bubble(s) are worked out, you might see teh level drop again. This could also account for the level dropping. It wouldn't account for the oil leaking into the water, however.

When you changed to drive lube, did you use new drain and level screw washers? Did you use the old ones, or are there none on the drive lube drain and check screws at all? This could for a small oil leak in the water.

Just a couple of thoughts.

Yes reservoir did overflow, it went from full to the low oil level. All oil on motor and in bilge. I put new gaskets on all vent and fill screws. I think I'll pull boat and check for water at lower drain and go from there. Thanks for the info, I too thought about an airlock and it heated up the drive oil enough to burp out the air.

[Cymru]

Last year that happened to me and I knd of ignored it because everything was running so well and the reservoir was full. Somehow there was a blockage in the line and then the line blew a hole and sucked up lake water that in turn screwed up the drive. It could be a lot of things but dont trust the reservoir as a failsafe.

[pascavone]

"a man got to know his limitations"..... Dirty Harry

get it looked at.....

[shrew]

Originally Posted by pascavone

"a man got to know his limitations"..... Dirty Harry

get it looked at.....

Ditto. I'm replacing my drive as we speak and they're not cheap. It's definitely worth pulling the boat and changing the drive lube again. also worth considering bringing in a merc mechanic. Small expenses now avoid large ones later.

[wooolffy]

Originally Posted by shrew

Ditto. I'm replacing my drive as we speak and they're not cheap. It's definitely worth pulling the boat and changing the drive lube again. also worth considering bringing in a merc mechanic. Small expenses now avoid large ones later.

I pulled my boat today, when I went to undo lower plug on sterndrive it was loose. I pulled it out and the oil was only slightly water logged. I inspected gasket seat area and there was a second gasket painted black. I couldn't believe my eyes. Oil had minimal water . I then checked reservoir and found sludge preventing alarm to sound as it didnt drop down enough.

Anyways the consensus was to refill with new oil, use one gasket, use a hammer screwdriver to tighten up plugs. Cleaned out reservoir,I also left reservoir low, below low level. When I tested in water the oil actually expanded up to full mark, then dropped when idling. I had originally filled it to full, no wonder why it overflowed. I learned something new today, I could not believe how much the oil reservoir fluctuated under various rpm's. Next year I'll be fillin her up to a low level., it was sitting at just above fill level when we docked.

Now to figure out my prop to rpm problem. 5500-6000 at 45 mph. Way to high rpm. On to the next adventure! Cheers to all!