I sometimes get a faint vibration that feels like it is coming from under the trike whenever I run above 65 mph. I also noticed a slight bit of grease slag in the areas surrounding the rear drive shaft joint. Nothing fresh or ongoing, but thought I would mention it. I don't know if it is the newer style drive shaft or the original because I don't have a visual reference for comparison, but I do have a photo or 2 of the drive shaft. How do I tell if I have the newer style shaft or the original? Is a slight amount of grease letting normal? Not sure I know how to post a photo here, but will try. BTW, it only has 25k miles on it.