82 gs1100 oil leak

[Greg7]

Noticed oil dripping from the rear of the motor while riding today. Got it home and cleaned everything up to see if I could find out where it's coming from. Couldn't figure it out so I took it for a short spin. So far I believe it's coming out of a tube which looks to be connected to a breather maybe? Circled said "breather/vent" in attached photo.

What part is that and what would cause oil to come out while riding ( if that's even the source of leak). Does not do it when just idling. ThanksIMG_20190609_181506.jpg

[Greg7]

From what I've found on the all knowing internet this is a secondary drive breather?

[bwringer]

Right, that's the breather for the chamber containing gear oil on the back left of the engine. The oil expands when it gets hot, so the air needs someplace to go.

Just a guess, but it's pretty common for people to overfill this gear oil chamber. You drain at the bottom and fill from the top, but there's a screw behind the shifter cover you have to remove that you use to set the level, about halfway up. So drain, then replace the drain plug and remove the fill level screw. Fill slowly until gear oil starts to dribble out. Then walk away for at least 15 minutes to let it finish dribbling. Replace the level screw and you're golden.

Yes, it's messy and gear oil is stinky. Use foil to direct the flow into a good size drain pan and attempt to keep it off the pipe.

[Greg7]

Right, that's the breather for the chamber containing gear oil on the back left of the engine. The oil expands when it gets hot, so the air needs someplace to go.

Just a guess, but it's pretty common for people to overfill this gear oil chamber. You drain at the bottom and fill from the top, but there's a screw behind the shifter cover you have to remove that you use to set the level, about halfway up. So drain, then replace the drain plug and remove the fill level screw. Fill slowly until gear oil starts to dribble out. Then walk away for at least 15 minutes to let it finish dribbling. Replace the level screw and you're golden.

Yes, it's messy and gear oil is stinky. Use foil to direct the flow into a good size drain pan and attempt to keep it off the pipe.

Thanks for the info. I changed the oil the other day and all is good so far. My concern now is that I bought the bike 2 months ago and probably put 700 miles on it so far. Never touched gear oil. When I went to change it I noticed the level was way too high. High enough where it was visible near the top of the fill plug now that it's at correct level I can't see it near fill plug. Figured if it was because it was overfilled by previous owner it would have been coming out the breather ever since I started riding it. Hoping it's not because motor oil is leaking into gearbox.....

[Greg7]

So after about 2500 miles gear oil started coming out of the breather again. Drained it and refilled with new gear oil. Seems to be getting flooded with motor oil. I thought the only reason I have to top of the oil every once in a while was because it's burning it but I guess there's a bad case seal between the gear box and crankcase??

[Grimly]

Major strip-down to replace the seal between the gearbox and the front bevel drive. I had one that leaked internally and just carried on riding it, knowing it was getting good engine oil all the time, so I wasn't worried. The XJ Yam in my sig, for example, has its front bevel running in engine oil by design, as do many other types of drive, so I'm not bothered. The engine with the leaky seal was eventually pulled, but not for that.