Leaky final drive

[sjbmw]

I have been riding my bike flawlessly all spring, 2 long trips, and all seemed well.

After a Sunday rainy ride home from Morton's spring fling, a buddy and I had a bike washathon at his house. I parked my bike on a driveway with an upward incline, and put it on the centerstand.
In 10 minutes, I had an puddle of gear oil on the driveway, coming from the rear boot on the final drive. Not a few drops, a puddle.

The bike has never leaked a drop from the rear boot when level, and the oil level inside is still near full. But put the bike nose up on an incline, rocked back on the centerstand, it leaked.

Any ideas why a drive would leak only when not level? Not a drop leaks when on the kickstand, or centerstand, on level ground.

[kirby]

Are you sure its coming from the boot? It seems that if the boot has no holes and the clamp/zip ties are snug it should not pass fluid. If the rear trans seal is leaking slightly it would most likely slowly fill the boot with oil. You probably will have to pop the boot and investigate exactly where the oil is coming from either the trans or FD.
Did you check the trans oil level as well?

[peels]

pop open the rear boot, look up in the swingarm. if theres a trail coming down, its likely the output (driveshaft) seal, which leaks then sends oil down into the back boot.. Ill sell you one of those for cheap LOL I'm fighting a gear lube leak. and bought one, that wasnt it. im not going replace it.

no trail up the swingarm, its the FD itself.

thats from surfing knowledge, only. Iv'e been exhausting myself looking into my problem.

[trickytree]

If it's a puddle then check the bevel drive, there's a lot less oil in there and it will be quite noticeable of the level is low.