Final drive seal
I wouldn't ride with a leaky seal-- mine failed all at once.
The consequences are too great even if the chance of it happening is small. The seal is not hard to replace. After removing the old seal, heat the rim by leaving it in the sun for a while, and cool the seal in the freezer. Lube the rubber part of the seal before installing it-- I have a feeling that the factory is not lubing the seals, as I've seen others here (including myself) with bum seals on a new bike.
My new seal pressed into place by hand and it hasn't leaked since (15,000 miles.) BTW, our bikes use the same seal as the police bike. While everything is apart, lube your rear driveshaft spline. Clean and wax your rear wheel, too- it's easier off the bike.
No other seals are needed, just some moly grease for the splines. If the old seal is stuck, drill small holes in the metal portion and thread sheet metal screws in. You can pry on the screws and not mess up the sealing surfaces this way. Clean out any shavings! It's probably a good idea to lube the splines on the wheel ever-so- slightly as well with some moly grease. kdhartley