bubbles in the lower unit gear lube

[slarson1us]

I changed the oil in my OMC 5.7's and the lower unit gear lube in my Cobra's today. I noticed when I drained the units that the gear lube had some very small bubbles in it, and when I refilled them, I think I noticed them again on the little dipstick at the top. The units have worked fine up to this point. I followed the directions on draining and filling (using the middle plug, the fill plug) and got all 64 oz of the stuff in the units. The dipsticks showed gear lube at the full mark as in the directions when I just placed the dipstick in the whole. I ran the motors after replacing the dipsticks and then checked the levels of the lube. The levels were fine again, this time at the full mark when I screwed in the dipstick, but I just think I saw some really small bubbles in the lube. Is this normal? I did notice that when I pumped the lube into the unit with one of the pumps you purchase that fits into the quart bottles, there were some bubbles in the tube as I pumped it in, but I don't know how you would ever not have that happen. It's not an air-tight system. Anybody have any thoughts on this?<br />Thanks,<br />Steve

 

[Don S]

Re: bubbles in the lower unit gear lube

What kind of gear lube are you using?

 

[rodbolt]

Re: bubbles in the lower unit gear lube

bubbles are normal. as long as they are air bubbles and tiny. what do you think happens when those gears whip the oil about during a run time. let it sit overnight and see if the bubbles are gone.

 

[slarson1us]

Re: bubbles in the lower unit gear lube

Thanks rodbolt. I left the boat in another city yesterday (Page, AZ) and I'll check it next time I go see it. I thought it might be normal. Don,<br />it's 80-90 wt. lower unit gear lube.