2020 Ford Fusion 2.0 AWD, 80,000 miles.
I bought this as my first real car in July, and since then I have put ~5,000 miles on it. So far I have loved it, but recently I have heard a few sounds from the RDU area that concern me.
Beginning a couple of weeks ago, I have noticed a dull or hollow thump sound from the rear. It only occurred when turning at slow speeds, and occasionally over small bumps (while turning slowly) It was not exceptionally noticeable, but I did hear it a few times over the week. I had some baseball cleats in the back, so I removed them, and the noise disappeared for several days.
I thought the noise could just be my cleats rolling, but as it turns out it was not. As I turned onto the highway up a hill, I heard a sort of crunch or grind from the same area, but this time, much louder.
I was already planning to do a change of the fluid in the differential, and I’m wondering if it could help. I also am unfamiliar with what the issue could be, and if this AWD system is known to be reliable or not.
any insight into this issue or past experiences with similar cars would be extremely appreciated
additionally, what fluid for the differential housing, I am getting conflicting answers as to whether or not it is 80w-90 or 75 SAE