Hi, I have an 08 rx350 with 202k km. All the maintenance has been done to spec. I have an awful sound coming from the back on acceleration, similar to a muffled hum. It's not the wheel bearings as those were recently done. I was advised it could be the rear differential. I was reading online and apparently it can be caused by bolts back there that may need retorquing. So I do not get ripped off, can someone please advise what to try first and/or look for? Thanks