2007 M35x clunking noise when accelerating over bumps?

[USMC5811]

I have a 2007 M35X with almost 100,000 miles and every time I accelerate from a stop and happen to drive over a bump, or sometimes even during a turn, I can hear and feel a loud clunking noise which sounds like it's coming from the rear.I'm not sure what it could be since it only happens when I'm accelerating from a stand still and will only happen up until I hit maybe 15-20MPH?

At first I thought maybe it's because it's AWD and the wheels skip a little when going over a decent sized bump and accelerating, but it's getting more and more common. At first i thought it only happened when I was accelerating from a stand still while making a turn and hitting a bump, but now I noticed that it doesn't matter if I'm turning a lot.

I tried to research the issue before posting but couldn't find any good answers.

1) What might be the issue?
2) Is it a common problem?

I also haven't changed the transmission fluid since I purchased the car when it had about 70,000 miles, but I'm assuming the previous owner did since he maintained the car very well and always had it serviced at an Infiniti dealer. Is the transmission fluid something I can do myself, and is there any other fluids that should be flushed and changed around 100,000 miles aside from the oil of course?

Thanks in advance for everyones help and input, it's greatly appreciated!

Semper Fi

[svard75]

Yup, happens to my AWD too. I don't really care what it is but can only assume it has something to do with the subframe bushings. I notice it more under harder acceleration. Sounds like you just ran over a large bump. I am up to date on all transmission and diff fluids so it's not that I also replaced the shocks recently so it's not that.