175 hp Yamaha lower unit question

[tigerhead]

Hey guys,
I just changed the lower unit oil on my 2000 model 175 Yamaha and I noticed some lube oil coming out of a hole in the case.  The hole is directly below the upper lube vent hole, so at first I assumed it was some oil that ran in there when I was burping the air out of the case.  There's not a lot coming out, very little actually, but it doesn't seem to be going away either.  I have been all over the internet and can't find any thing that shows me where that hole leads or what it's for.  I thought it might be a tattle tale indicator that let's you know when one of the seals is leaking.  However, I didn't have any indication of water intrusion in my old oil.  You can see the hole in the attached image.  It looks like a slit in the image but there's actually about a 1/8" diameter hole in the left end of a groove.  Any help would be appreciated.

[gnrphil]

Interesting sorry I can't help but I'd guess you have a seal leaking.

[mcsd63]

Hook the muffs to it. It should be a weep hole for water to drain out.

[985crabs]

Mine's a 2003 and it doesn't have that groove/hole, but I think mcsd63 is right. Mine has 4 or five weep holes all over the lower unit. If it is, then gnrphil is probably right and you have a seal leaking. You sure it's lube oil? Could it be post-combustion exhaust oil?

[tigerhead]

Thanks for the replies.  Definitely lube oil.  I was hoping to get out of doing a seal job but I may have to bite the bullet.  I'm going to bring it to a mechanic and have him pressure/vacuum test the gear case.  That will tell me if I forced oil through a seal and caused a temporary leak or if I have a damaged seal to replace.

[tigerhead]

For future reference, I had a pressure/vacuum test performed and the seals passed with flying colors.  I definitely forced some gear case oil through the seals but apparently did not damage the seals in doing so.  Refilled gear case and unit is doing fine.

By the way, the drain hole that had oil coming out of it was unrelated (sort of) and was a false positive.  That hole is there to drain water out of a recess in the casting outside of the seal gland casting.  The oil that was coming out of that hole had made it's way into that casting recess, through that same hole, when it was running down the side of the lower unit.  That can easily happen when the oil comes out of the vent when filling the gear case.  I probably confused some people with that explanation but bottom line, no issue.