2007 G35x, bought it used and it was evident it had been in an accident. The owner must have done the work "off the books" as there was no reported issues. Got it with about 110,000 miles and at first it ran fine. I'm now up to about 149,000 and a strange development has come about. If I try to accelerate hard from a stop, there is a loud knocking (almost banging) sound from the front wheel wells, mostly the left side but sometimes from both. I thought it might be the transmission, but it seems to be shifting fine.
It’s almost as though the traction control is kicking in, but it occurs on dry pavement. If I’m turning the wheel at the same time, it’s worse. Also, if I try for hard acceleration after a hard stop, it’s really bad. If I’m at highway speed and hit the gas to pass, the issue does not present itself.
I thought the bearings might be binding, so I replaced the hub/bearing assembly on both axles, but the problem persists. I tried to change out the front diff fluid, but in my attempt to take out the top fill plug, since I couldn’t get the 10mm bit to seat firmly, I ended up stripping out the plug.
Any insight to what might be wrong will be greatly appreciated.

 

Is it CV axle clicking that's very noticeable when turning a slow corner with the steering wheel at full lock?

If not then I'd start looking at the ball joints.

 

It's not what I would describe as a "clicking" sound, more like a hard knock. It's not present all the time. As for the joints, I have checked them out and there's no play. It's bad enough that it mechanically causes the car to stutter during hard acceleration from a stop.

 

Are you in Minnesota by chance?

 

I am indeed

 

Well, I think a person would def. have to witness this, ( after i reread your original post) in person, to many things come to mind. The sway bar is in good shape? and the bushings? I am in Delano.

 

I'm trying to figure out a way to set up my cell phone to record the matter. As for the sway bar, I don't think that's it. It's almost like the traction control is kicking in and clamping down on the brakes.

OTOH last night as I was coasting at a slow speed and changing lanes, I heard the same knock - with no accelerator input.

 

Here are a couple video clips
https://youtu.be/wu-ZL9QU1qA

<iframe width="560" height="315" src="https://www.youtube.com/embed/wu-ZL9QU1qA" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

 

Sounds bad bro , good luck and keep us posted

 

Thanks for doing the link, never could figure that stuff out. As for the issue with the car - I'm stumped

 

That noise is suspension related somehow, CV axle click is rhythmic according to wheel revolution. I can clearly see your suspension traveling up/down exactly as the noise is happening.

It looks like you should be able to replicate the noise simply by bouncing each corner of the suspension while parked. Pop the hood and trunk so you have something solid to push against and see if you can replicate the noise, if you can then it will be easy to find the culprit.