lower unit

It may be oil from the engine and not gear lube. If it is gear lube, and that is the origination of the source, then you may have a major problem. Have it checked out ASAP so that your at least safe if not upset by the damage. Perhaps you wont be as upset if you save some parts.

It sounds like you are talking about the water intake ports (merc has changed the opti gearcase more than once, but it sounds like you have the low-water intake on the front of the gearcase torpedo?) I would be tempted to drain the L/U completely. Drain it into a pie pan or something similar so that you can see the oil clearly after it is all out. Any sign of water? Milky? Id do this a day or two after the last run as WOT will froth up the oil like crazy and water will emulsify and suspend in the oil. I usually drain with the motor _slightly_ tilted up so that the drain plug appears to be the lowest point in the gearcase. If it looks good, re-fill and dont worry about it, other than to do regular checks just for safety. Just helped a family member solve a problem like this where he waited too late. He spent about 2300 bucks to buy a reman L/U from the local merc dealer. Not cheap. Note that if you happen to have synthetic oil, and wait a day or two to check it wont be milky. The water will drop out and go to the bottom as a little puddle. I park my boat with the motor over a metal pie pan. If I notice anything in it, it gets my attention. I drain a few drops every time I go out just to check. I keep a bottle of oil close by where I park the thing to replace this after 2-3 checks have been made. Note that water intrusion doesnt mean you are facing a huge bill. yet. But if you wait, water will ruin bearings and/or gears, and then you will have a whopper. There are seals all over that L/U. Double-seal on the propshaft. But also a seal on the top of the gear shift shaft, at the bottom of the water pump housing, the driveshaft… any one going out, getting hard, or whatever can start a problem that is initially cheap to fix if you notice water in the oil, or you notice oil leaking out. The sooner the problem is fixed, the cheaper it is. If you are not a do-it-yourselfer, Its probably worth a 100 buck trip to a shop for a check.2008 Pantera Classic2014 Mercury Pro XS 200

Heres the key point. You can run the stew out of that lower unit, and if you are religious about checking the oil, it will last almost forever. I have a 1992 XR6 that uses the smaller torpedo gearcase which merc dropped a few years later due to reliability. I have replaced the seals multiple times, whenever I detect water intrusion or oil leakage. I dont pass go. I dont collect $200. I go directly to my dealer, buy a 40 dollar seal kit plus a new water pump impeller while I am at it, and replace everything. It is hard to determine exactly where a leak is at times. If you replace all the seals, you are once and done, which is the way I like it. I know many others that have had gearcase failure after failure. As in the one I mentioned. Motor made an odd “clank clank” (not that loud) running down the river. Owner drove it up here and we took it down to Lay. The clanking was clearly related to engine rpm, but at (say) 3000 RPM the clank was about once every second and a half or so. Only possible explanation I could come up with was a missing tooth on the main pinion and prop drive gears. Pulled the drain plug and had some metal pieces (not the almost metallic dust you normally see). Pulled the prop and the bearing carrier and there it was. Lots of rust everywhere. And two completely missing teeth plus a couple on either side that were chipped. When they lined up, the gears could slip, producing that metallic “clank clank”. He chose the quick way out and bought the reman unit. Probably would have cost about that much to replace the gears, the bearings, and everything if there was no hidden damage that only becomes apparent when you pull the gears and driveshaft out. Ive always been suspicious of L/U oddities. If it doesnt quite seem to shift into reverse properly. Out comes the bearing carrier. If it pops out of reverse while backing up. Out comes the carrier. The quicker you investigate a problem, the cheaper it is to repair. And from my fairly lengthy experience with outboards, not many problems just “fix themselves and go away.” It might appear to be so sometimes, but they will return. With a mighty big bill accompanying them. Sort of like sticking yourself with a dirty nail. You can treat it easily when it happens. Wait until it gets infected and it is a bigger problem. Wait until it turns into gangrene and it becomes a bigger problem still. The longer you wait, the more of “you” you are going to lose.2008 Pantera Classic2014 Mercury Pro XS 200

remember that 1500 degree + exhaust goes right thru the middle of the thing. It can get quite hot from that, even if there is zero friction internally. Theres a channel thru the lower unit, thru the bearing carrier that is exposed to hot gasses.2008 Pantera Classic2014 Mercury Pro XS 200

thanks for the info, i knew that the exhaust went though the lower unit but i figured that the prop would feel warm too, i just put new fluid in it about 2 months ago, i will check again though. thanks for the info

What went wrong? Did you shear a pinion gear? Clutch dog blow up? Broke the prop shaft? Drive shaft?What oil are you using?Keep in mind you get what you pay for. I dont like the castings on the imports.

There is no safety concern, the cases are the only differece in newer and older Pro XS engines.