Last year, on my 2006 ...I sucked out about half the oil using a Mity-Vac, and then replaced the oil.... will do it again this year... I hope that works... the tranny is a ***** to get to, so when you are there.... do it man...
Thanks, that's what I will do. I will extend the tube to the outside via a newly drilled hole in the back using the same air vent although the vent will be removable so I can refill without taking the seat and rear fender and gas tank out. I will also fabricate a "Dip stick" and mark the full point on it for future use (1-1/2 Inches below the top of case. Next year I will drill out the welch plug and allow it to drain and then cut threads in the hole, flush, screw in the plug and refill to the proper level using my dipstick and the replace the air vent. Then it will be serviceable without having to remove any major parts. In fact, I just may do that to my GT6000 later on if it has a place to drain on the bottom and a filler hole on the top.If I remember correctly... it's supposed to be about 1 1/2" from the top of the fill plug....
I'd leave it for now and next spring do the same thing and that should re-juvinate your oil good enough for a few years...
Good luck