ticking tranny

[HRC_rider]

My 05 R has been ticking after the past few rides. Not like an exhaust tick but rather like a leaky seal. Tonight I tracked it to the transmission. If I press the drive sprocket or load the rear suspension the frequency changes. In addition there seems to be a very small oil leak behind the sprocket. It's not at the shifter and the chain has never been thrown. Am I going to need to split the case to get at this seal? I hope the bearing isn't beat too.:(

Anyone had this problem?