I bought the 2012 Acura RDX FWD with 111k miles (automatic transmission) 9K miles ago and during a pre-purchase inspection a mechanic noticed a minor undercarriage vibration when accelerating. He pinpointed it to the left and right front axle shaft assembly so a mechanic replaced the CV boots, CV joints, and left/right axle. Everything was fine up until ~109K miles I started hearing suspension creaking when going over speed bumps, which now occurs over any minor bumps really. It sounds like it’s coming from the front left side but more towards the center of car.
I also started noticing vibration/wobble in the steering wheel when accelerating at higher speeds (~65 MPH). It stops once I let off the gas pedal. I’ve had one mechanic say the vibration/wobble was from unbalanced tires (it wasn’t… still occurred after balancing) and another say front inner joints being worn out was the issue and should replace both front axles. I don’t see how this is possible if they were replaced 9k miles ago? Anyways, I had yet another mechanic say the creaking in particular is likely from the struts, but I’m not so sure about that either. There doesn’t seem to be any residual bounce after bumps and I don’t see any leaks… though they are pretty rusty. I’m curious what could actually be causing the creaking and the steering wheel wobble. I’m sure it’s likely two different issues, but what mechanics are telling me isn’t making sense.
The creaking noise is most commonly caused but the strut mounts themselves. However it is recommended to replace the entire unit when possible with what is called a Quick Strut Assembly. This replaces the mounts, struts and springs all in one assembly and can typically be done in about an hour per side.
As for the vibration, I would move the front two tires tot he back of the vehicle and test drive to see if the vibration moves with the tires. A busted internal belt is quite common. And this is a way to test first before replacing if needed. The vibration may be felt more in the set than in the steering wheel if the vibration follows. The next most common cause for the vibration/wobble would be the hub bearings going out. But generally you would hear some noise at slow speeds as well, but not always. Vibration/noise is difficult to pinpoint at times. Here is an excellent article on how to approach a problem such as yours.