Gear Oil Leak on G27A

[apd628]

I recently acquired a 2006 G27a Umax. It has a gear oil leak coming from the right side of the differential. I checked and it is not coming from the inspection plate.

I checked the gear oil, and it was low. I brought it to the bottom lip of the fill hole, and drove it after I cleaned all the gunk off the axle. After a 30 minute drive, the right side of the axle housing where it mates with the differential was wet with gear oil. The brake-wheel end is fine.

This is deja vu all over again, as I have a love hate relationship with my
1975 Harley FLH and it's oil leaks that come and go. They usually only go after hours of busted knuckles on my end.

The oil is gear oil, not crankcase oil, which stays at the full level. I have replaced several axle seals on pick up trucks, is this a similar process?

Otherwise, this Yamaha is a blast to drive around on, and behaves very well.

One last thing, is there any such thing as a heavy duty version of a G27A Umax? Reason I ask is that mine has drum brakes all the way around instead of just on the rear axle.
Thanks