I'm about to buy a tri-ax soon and heard that royal purlpe tranmission oil will help with the whine of my 3650. If it does help then i want to change it out. How hard is it to change it? I consider myself an ok mechanic so i'm not really worried, but I looked under the tranny and didn't find anywhere to drain it. I'm sure i'm missing something. Any info/links/advice would be great. Thanks guys/gals.