I'm a bit confused about the service interval for the rear differential for my Gen 3 2009 CR-V. I have read that the fluid should be changed every 30,000 miles but I've downloaded the excellent forum DIY guide on the topic which says service at 75,000 miles or 8 years. My car has done 87,000 miles but documents that came with it confirm that a Honda garage changed the diff fluid at 37,000 miles. Should I change the fluid now? Any advice would be appreciated.