I have a 2004 G35 coupe and have been hearing this noise occasionally when I go over bumps or just going at low speeds or making a left turn. The weird thing is, the noise is not present on every bump, pothole etc, and even occurs on relatively sooth parking lots. I was able to constantly replicate it with yanking the car to the left (0:00-0:05 sec of the video). Doing the same to the left has no effect.
I jacked the rear using the included jack (dont have anything else at the moment) and there is no play or any abnormal noise, everything looks solid.

I know axle makes clicking noise and its an easy fix, but mine doesnt sound like the axle click. I will be going to a DIY garage with a lift to do a diff fluid change and to find what causes this noise. Anyone has a suggestion what too look for?

 

Check the boots on your axle shafts to see if they are torn or leaking grease. I can't see the video at the moment from behind my work's firewall, but that's just a general recommendation based on your problem symptoms.

 

they are perfectly intact, no tears or leaks

 

Can you tell from which part of the car it's coming from? Front/Back, or maybe one specific side?

 

It's from the back, but I'm not entirely sure left or right, kinda suspect left though. Cuz when I yank the car to the left the sound is present and not the way around

 

Often times suspension noises are made on the opposite side of the direction you are turning since turning right loads the left side suspension, and vice versa. Possibly a worn or completely disintegrated bushing?

You don't have any loose stuff in your trunk or back seat that's moving around and banging against things, right? Tools... .floor jack... a bowling ball... LOL.

 

The bushings that I can see from jacking one side at the time are fine. I will be able to check all of them on Sunday at the garage. But nope, I emptied everything, even the spare tire and folded the rear seats lol Same. Actually folding rear seats made the sound a bit louder

 

I'm never thought to look and see how G35's secure their boots to the axle shafts, but I'm assuming it's a standard Oetiker or CV-clamp. Do you own or have access to one of those tools used to reinstall those clamps?

It's probably best to start out by pulling back both CV boots (inner and outer) and checking them for grease and maybe repack them with a good Moly grease for axle shafts.

 

Yeah, that garage has that tool, and can I do that without pulling the axle out? But if the axle is shot, will those be a fine replacement? http://www.autozone.com/drivetrain/c...?checkfit=true

 

I doubt your axle is shot but it may need to be repacked with grease. Not sure about that replacement CV. The key is to address it early when you start hearing or seeing noises or seeing any grease leakage.

 

Ive been hearing this noise for a while, maybe over a month, but I couldn't address it due to lack of time and money... I'm going to re-grease them on Sunday and see how it goes.

 

Hmm, I have the same thumping sound, just quieter and coming from the back.

 

If it is indeed your axle and it's clicking already, I would just replace it vs. repacking it with grease. It could be all pitted or damaged already from excessive wear due to lubrication breakdown or something. Plus, it's a messy crappy job, lol. I rebuilt the CV joint on my Volvo before I gave it to my sister, since it was a 30 dollar fix vs 150. Well, I got it all good and tested it for a few days and when I was leaving the parking lot it ended up failing on me anyway. Luckily, it was in the parking lot and I was able to tow it, but then had to spend 300 for the mechanic to do it in a rush, since my sister was leaving and she needed the car.

After that I swore I would just replace axles now and not bother rebuilding the joints, lol. Which, is a dilemma I'm facing on my Audi now it needs a new front axle.

I'd start with the sway bar bushings and end links in the rear or just replace those while you're back there.

 

Suspension noises are notoriously hard to isolate. Since it does it while turning left, I'd focus on the right side of the car (turning left causes a load to be applied to the right side).

Swaybar endlinks are an obvious target. If you can twist the endlink with your hand, then it's worn out and should be replaced.

Another problem area is the shock mount. The bushing tends to wear out and cause a clunk. These cars are getting old and shocks are most likely worn out, but most people only seem to replace them when they're totally blown (bouncy, seized, etc).

Another item could be the rear differential bushing, those are liquid filled and leak goo all over the rear subframe/diff/exhaust pipe when ruptured. But it's probably not you issue since the noise is when turning and not on acceleration.

Swaybar and shocks are where I'd focus my attention. Let us know if you find something out.

 

Yes....definitely sounds like sway bar end links