Drivetrain CLUNK during Low speed Acceleration is this normal? (youtube video)
 

Hi, i'm experiencing a sound on the rear of the car during low speed acceleration driving 15mph or lower, it feels like there some play between the engine - drive-shaft - differential. I have visited two dealers and both dismissed it as normal. I have a friend with a 370z and he has never noticed on his car and did right away when we tested mine.

I have an schedule check with the warranty claims guy this week, i'm not sure how successful will that be. Does anyone has a drive train as noisy as mine?

YouTube - 370z low speed drivetrain clunk

This was recorded using an iphone, please turn your volume up!

sounds like ur accelerating and hitting the clutch right away abruptly to me... i can reproduce that sound if i wanted to, but i dont drive like that. Try slowing letting off the gas and and then getting on the clutch

The thing is i'm not hitting the clutch at all, Just driving 5mph then accelerating until 10mph.

One of the diff mounts possibly has come loose? Years ago I also had a car with a bad diff that would do that, can also be a bad CV joint in the half shaft.

Did the dealer even look at it?

One dealer claimed to had looked at it and then told me it was normal, i have re-visited this dealer and also verified with another dealer and the result was the same. I have an scheduled check with the warranty claims officer from nissan tomorrow. I have 31k miles and haven't noticed it before I hit 30k... a friend of mine also an 370z owner hasn't noticed it on his, it has 14k on the odometer.

If it doesn't go well with nissan, i'l have to go to an real mechanic to get this checked and to install FINALLY my berk HFC's.

Definitely doesn't sound normal, does it have a feel to it as well? I.e. does there feel like there is any slack in the drive-train?

One tip for doing these that made it so much easier. Completely remove the drivers side air intake filter box. There is only one bolt that holds it in place (disconnect the intake hose obviously) and then it just pulls right out. If you do this then you have a completely straight path to the dreaded demon bolt which means you can just use about 36 inches of extensions and don't need a universal joint in the middle.

There's some slight slack in the drivetrain, I strongly belief this is related to the driveshaft joint. But i'm no mechanic, and I don't have ramps to verify. It feels very similar to when my last car had bad engine mounts, it was FWD.

The drive shaft universal-joint is incredibly strong and so seldom fails, however the CV joint in the half-shaft can wear out and will exhibit the same symptoms. Usually takes a lot more than 30k miles though.

6th visit...
 

The dealer has yet to find out the issue, they dismissed it as normal, then when i talked to the service manager, he scheduled a check with the local nissan rep, he rode shotgun today to verify the sound and has no idea... sight... these people wont do anything unless you push them along or your car basically falls apart.

he will notify me next week with findings, If he dismisses it as normal I will have to go with another 370z owning friend to show them that the sound is not normal or characteristic,.. I have a feeling this will be the case... :shakes head:

I would recommend changing your differential oil to something thicker like Motul 90PA... that could be the issue. I was having issues with a whining noise coming from my diff at low speeds and and the fluid change resolved it.

Unfortunately the sound i'm complaining about is not the diff whining, its actually what seems a metal to metal contact noise, as if slack somewhere along the drive-train leads to two metal parts hitting against each other under weight shift as a result of acceleration.

It's really hard to tell from the video being inside the cabin. I turned my speakers up all the way and could barely hear it. If it's metal on metal then it could be anything from the driveshaft to the axles. I hope you get it figured out.

FIXED!... Nissan local rep had to step in, they said they worked on the right cv joint. Finally clunk free!.

ChrisSlicks you were spot on, figured out from a youtube video, had to go to the local dealer 5 times for them to figure this out. Rep!

Cool man. Can't believe that the dealer was so ignorant on the problem.

So that's normal and nothing to be worried about? I'm definitely having the above issue when I disengage the clutch from 1st to 2nd and less so from 2nd to 3rd. You can hear that it kind of has an echo to it. Just got the car this week ('09 with 5000 miles). Admittedly, I'm still getting used to the clutch and especially how the RPMs like to stay high and come down slow when you push in the clutch and are off the gas. And as you can see/hear, letting off the gas doesn't alleviate the problem. YouTube - 370Z clutch THUMP Thump thump.

That's not normal.
What RPM are you shifting @?

Im getting a clunking noise also, its usually in first gr or reverse. And it happens when completely off the clutch. I cant pinpoint where the sound is coming from, but I checked the front end and exhaust, both seem fine. I'm going to check the rear axle nuts next week, hoping its something easy...

Gunzero,

I'm shifting right around 3-4000 RPM. Thanks!

It shouldn't sound that way then.. I don't know what the problem is. Perhaps, a bad clutch. You're welcome :)

I'll try to post a video of the way my clutch sounds. TTYL

What does it sound like? :)

I second; everyone should check your rear axle nut on the driver's side. 2009 370z did not use a locking sleeve over the axle nut like 2010 and 2011 model Zs, and this can cause the axle nut to loosen up about 2-4 turns before being stopped by the cotter pin. Threadlock, a 1.25" deep socket, and a proper torque wrench should do the trick.

Mine was loose less than 6 weeks ago, had to tight it up and I double checked the pass side and it tight

Wow! You all got me worried. Because mine makes noise going and coming out of first. I dont know much about this kind of stuff. Which bolt are we talking about in the left rear axle? I dont have the smallest idea. Can someone do me a huge favor and explain to me more or less which one? Does anyone have a pic of it or the general area where it is? Thanks a bunch in advance. I dont have warranty due to mods and I cant really afford for anything to break on this thing. Thanks.

Z is doing the same thing. Ill be putting it on the lift and taking some pics for everyone

The same thing as mine (clunk when disengaging clutch?) or as GonGo's?

Size 32mm deep socket

any pics or videos yet? ive had this for almost two years now and dealers say its normal but i never had this clunking noise in other manual. glad to know theres a solution for this.

Anyone have the torque spec for the rear axle nuts from the service manual?

The service manual says 133 ft/lbs (180 Nm).

Thanks

Maybe this will help:

Clicking Noise from Rear Axle, - MY350Z.COM Forums

So what was the cause? A right CV joint? I think I'm beginning to get a similar problem. If i'm off throttle coasting and then get on the gas i get a faint clunk sound as soon as i push the throttle in. It sounds like metal on metal contact, as if there is excessive slack somewhere in the diff or axles, and revving the engine takes up that slack, but causes a clunk when the metal parts first collide.

I have something similar on a 2010roadster with 2000 miles on it. Been there since day one.