Wife heard a loud clunk and thought someone rear-ended her a couple days ago. No crash. Just the Rav4 making weird noises. After several tries over the years, I've finally got the rear differential bolts loosened. Some fluid dripped out of the fill hole. It was the color of coffee with cream in it. It's the factory fill. I drove it today and it drove pretty well. Some pulsing in the transmission as it downshifts. Think it's worthwhile to change it out?