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

GonGo

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!

CCastro

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

GonGo

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

ChrisSlicks

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?

__________________
Hotchkis ARB | Stillen CAI | Art Pipes | Berk CBE | Stillen AP Racing Brakes | AE Performance Oil Cooler | BC Racing ER Coilovers | Doran Control Arms

GonGo

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.

ChrisSlicks

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.

__________________
Hotchkis ARB | Stillen CAI | Art Pipes | Berk CBE | Stillen AP Racing Brakes | AE Performance Oil Cooler | BC Racing ER Coilovers | Doran Control Arms

GonGo

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.

ChrisSlicks

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.

__________________
Hotchkis ARB | Stillen CAI | Art Pipes | Berk CBE | Stillen AP Racing Brakes | AE Performance Oil Cooler | BC Racing ER Coilovers | Doran Control Arms

GonGo

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...

Staples

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.

__________________
'08 Infiniti G37s - Forced Induction Fed

GonGo

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.

Staples

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.

__________________
'08 Infiniti G37s - Forced Induction Fed

GonGo

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!

ChrisSlicks

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

__________________
Hotchkis ARB | Stillen CAI | Art Pipes | Berk CBE | Stillen AP Racing Brakes | AE Performance Oil Cooler | BC Racing ER Coilovers | Doran Control Arms

Grunj

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.