redlinernyc

Hey guys,

I have a 2014 Nismo 370z and I posted this issue on the Z forums but looking for more input. Since we share basically the same car, I am asking here for some assistance.

2 weeks ago Nissan put a new transmission in my car due to grinding. 16k on the car. About 170 miles on the new tranny and while it shifts great now, I'm noticing an issue. In all gears at low rpm (1100 - 2000) the car chatters and rattles a lot. I had a lightened flywheel in my old 350z and this sounds the same, except I'm running an oem clutch and flywheel. I don't typically drive in this low of an rpm range but after the tranny was installed, I was really testing it out and noticed this during a rolling stop in 2nd gear accelerating.

For instance, 3rd gear at 1100 rpm and it'll chatter and rattle and pretty much stop after 2k.

This issue only happens when the car has been driven some time and never during the first few miles of a drive. So it's temperature related I guess

Dealer had it for 2 days, did a thorough test and basically said nothing is wrong.

I found this video and at the 0:28 mark is the noise I hear. Should this happen with an oem setup or did I receive a defective transmission?


Appreciate any input you guys have. Thanks

redlinernyc

bump.. anyone?

Surfnazi

When they changed the trans did they put in new clutch and throw out bearing?

steezy

Sure it's the flywheel and not your catalytic converter?

SonicVQ

Our cars have a dual mass flywheel and it sounds like yours has some play/rattle in the bearing that holds the two "masses" together. I suspect a new flywheel is needed.

Different car, same noise:

redlinernyc

Thanks for the feedback. How can I be sure it's not something internal within the transmission? To reiterate, it's temperature related. No noise on a cold car. Once it's been driven around for a bit and gets really hot, then the noise starts. I was thinking input shaft bearing rattle?

SonicVQ

I thought about the input shaft as well, but since is a new transmission I don't think that is likely.

Since it is temperature related, there is a bearing that has too much play when warm. The challenge is, finding out which bearing. I think you should shoot your own video and show it to the Infiniti service advisor.

Good luck!

redlinernyc

Here's an old video from last October. You can clearly hear the rattle that happens between 0:02 - 0:04 seconds. Thoughts?

SonicVQ

The video is very helpful. The rattle happens at the point of clutch engagement.

Since you have had the same noise with TWO different transmission, I think we can rule out any tranny issue like input shaft rattle.

As I see it, it is now down to:
(1) Dual mass flywheel
(2) throw out bearing

I would expect the tech who installed the new transmission, to check the throw out bearing.
Either way, the tranny has to come out to have look -or- live with the noise.

In the warmer weather, I will shoot a short similar to what you did, just to compare.

redlinernyc

You know, I never noticed the old transmission making the noise when I drove it. That's because I wasn't keeping an ear out for noises. The old transmission developed a grind, which is why it was replaced. However, I did the valet drive my car one time and as he reversed the car (I was outside the car) I did hear the similar noise that's in the video I posted of the new transmission.


And I wouldn't think the input shaft would rattle based on how hot it gets. Wouldn't it rattle even when cold?

SonicVQ

As metal parts warm up, they expand just a little. Sometimes that can cause a noise to go away, or to start.