Drive Lube Oil Issues

[Hunter]

I’ve got a 2006 260 Sundancer with a 350 Mag MPI and Bravo III outdrive. Yesterday the boat was out for most of the day and had no issues. This morning I went to start it up and the low drive lube alarm was going off. There is oil splattered everywhere, likely from dripping on the drive belt while it was running yesterday, and when I removed the cap to the reservoir all the threads were coated in oil as if it was pushed up and out the top of the reservoir, but it’s empty now. What could be the cause of this?

Thanks,
Hunter

 

[BillK2632]

Check the cap and make sure the gasket didn’t go missing.

 

[Lazy Daze]

A couple things. You didn't mention if this was one of the first trips after a fluid chang and your signature doens't show a location, so for now I'll assume... After a fluid change, it's not uncommon to get air bubbles. It's also not uncommon for the oil to heat up a bit and expand. Combine those two things - especially if the fluid was "topped" off pretty high before the air bubbles worked themselves out, and you could have had expansion, then the air bubble worked it's way out.

Clean everything up real good, fill to the normal level, monitor.

 

[Hunter]

Check the cap and make sure the gasket didn’t go missing.

I just did, everything appears to be there still

 

[Hunter]

A couple things. You didn't mention if this was one of the first trips after a fluid chang and your signature doens't show a location, so for now I'll assume... After a fluid change, it's not uncommon to get air bubbles. It's also not uncommon for the oil to heat up a bit and expand. Combine those two things - especially if the fluid was "topped" off pretty high before the air bubbles worked themselves out, and you could have had expansion, then the air bubble worked it's way out.

Clean everything up real good, fill to the normal level, monitor.

Unfortunately, the oil hasn’t been changed in a long time and if anything it was a little lower than normal, as I haven’t topped it off recently. I read somewhere about water leaking into the outdrive and causing similar symptoms, and my biggest fear is that I’ll put more oil in, run the engine, and then end up ruining internal components.

 

[scoflaw]

Have a look at your oil when you change it. Check the fitting and hose on the plastic bottle

 

[Lazy Daze]

Unfortunately, the oil hasn’t been changed in a long time and if anything it was a little lower than normal, as I haven’t topped it off recently. I read somewhere about water leaking into the outdrive and causing similar symptoms, and my biggest fear is that I’ll put more oil in, run the engine, and then end up ruining internal components.

Well, that definitely changes things. Hopefully you're at least using the Merc Hi-Perf gear oil - that can deal with a little water intrusion.

Next step - should be done before the boat is run again, drain the fluid and check it out. Post back after that and we can go from there.

When you say "a long time" - what timeframe is that? This should be done yearly or every 100 hours.

 

[Hunter]

Well, that definitely changes things. Hopefully you're at least using the Merc Hi-Perf gear oil - that can deal with a little water intrusion.

Next step - should be done before the boat is run again, drain the fluid and check it out. Post back after that and we can go from there.

When you say "a long time" - what timeframe is that? This should be done yearly or every 100 hours.

Yeah, I use the Mercury High Performance gear oil. I was hoping it could be something simple that doesn’t require pulling out of the water... It’s possible that there is a leak in the pipes, but that wouldn’t explain why all the threads on the reservoir and in the cap were full of oil.

I guess the first step will be to fill it back up and check for leaks.

 

[Lazy Daze]

I agree that it's the oily thread part that has me worried. If the bottle leaked out the bottom (crack), there's no way the threads would be oily. The bottle definitely bubbled over. The question is "why". Now, the level must not have been too low or you would have had an alarm. BUT, I would highly advise against using it till you pop it back on the trailer and drain/check. To me, that would be the first step.

 

[BillK2632]

Only 3 ways gear lube can leak into the bilge:

• Lube bottle.
• Hose from lube bottle to transom.
• Upper drive seal leaking into u-joint bellows and eventually into bilge. (This is bad and least likely to be the problem).

Clean everything up, check the bottle and hose and change the gear lube to set a baseline. My BIII always used a little gearlube, but never leaked anywhere that I could tell.