My Z sounded like that for over 4 years. It made the funny clanky noises as well as the vibration when I shut it down.

I'm not sure if this rectified the shut off vibration or not, but when I changed my tranny fluid from OEM to Redline it stopped. Coincidence, maybe? Maybe not. I'm not sure...

 

Mine did that on both transmissions (replaced 2 years ago). I'm getting fed up with the clunk and difficulty getting in gear. It was buttery smooth the first few months after getting the replacement.

 

If its hard to shift into gear, its your syncros. Even deeper, its the dogteeth (not tech term) thats not catching the gear to let you shift.

 

OP that is not your tranny that is making that noise.

It is your muffler bearings. Get to the dealership and have them pull your cat pipe and inspect part #236912(a). There was a TSB on this.

 

To the OP: That is definitely gear lash noise. I wouldn't worry.

 

My Z32 tranny does the exact same thing.

 

Thanks man. I have an aftermarket catback now, so it won't be under warranty. I went ahead and ordered two of these muffler bearings though

http://kalecoauto.com/index.php?main...948641e9caf193

 

Not to hijack this thread nut I have a comment and a question. I too had that rattle when the clutch was out in neutral. I just put a Jim Wolf clutch with a new throw out bearing and a new input shaft bearing and it's gone. Since we are talking about sounds, what's up with that pop sound right when the engine turns over? Seems to be louder the longer the car sits.

 

muffler bearings?? what?

 

please tell me your kidding about buying muffler bearings

 

No, I received and installed them this morning. The noise in the video is 100% gone!


My exhaust is also made by the same company. I had the stock muffler cut off and they welded one of these on - it's pretty BA.



"You've heard of the Y pipe.. the X pipe.. the H pipe.. nothing can touch the O pipe!!! It provides 100% back pressure feedback on ALL engines!! Torque increase and kuneutson valve float brings in much lower revs so you don't hurt your motor! Not CARB Legal. Please specify standard or polished finish. Product shown is single input O-Pipe with polished finish."

http://kalecoauto.com/index.php?main...948641e9caf193

 

Its the normal sound of the transmission input and lay shaft being rotated with no gears engaged AKA neutral. The sound will amplify and carry to 2000RPM with a gear engaged if you purchase a non dual mass flywheel. Its nothing to be concerned about and is totally normal.

 

This is independent of gear selection. It is gear lash noise.

http://www.uucmotorwerks.com/flywheel/gear_rattle.htm

 

In order to have gear lash noise you must have rotation of the gears correct? You dont just put two gears together on a table and then suddenly they make noise. The input shaft gear spins the lay shaft gears when the engine is running and the clutch is engaged. Its easier to hear the noise when your in neutral and sitting still rather than accelerating/driving the car. That was the point I was making. If you notice in the numerous threads on this site most people only complain about the noise at idle until they get a lightened flywheel. Then they can clearly hear the noise when accelerating until a certain point. With my car I hear it until 2000rpm and then it cancels out. I emailed JWT about this since I bought and installed there flywheel in my car. Heres the email they sent back to me.



Hi Charles,
Here is some information on the transmission sound when changing from
a dual-mass type flywheel to a conventional solid flywheel. This is
from a Sport Compact Car Magazine article on their project 350Z.

"In a quest for smooth, quiet drivetrains that are strong
enough to take relentless abuse, Nissan has adopted dual-mass
flywheels on all (both) its new engines. Big, strong gearboxes like
the one in the 350Z/G35 tend to rattle and groan like a UPS truck at
low rpm. The noise comes from torsional vibrations originating from
the surge of individual power strokes. A dual-mass flywheel
separates the crankshaft and clutch sides of the flywheel by a set of
springs. Using the power of math, Nissan engineers chose appropriate
spring rates and flywheel mass to damp out these vibrations, making
the gearbox smooth and quiet and eliminating complaints from those
who would whine about funny noises.
Unfortunately, that math also shows Nissan engineers the Z/G35
flywheel has to be 25.5 pounds to damp things properly. That doesn't
seem overly heavy when a quick a quick zing of the throttle unleashes
274 lb-ft of torque, but when we replaced that 25 pounds with 14
pounds of Jim Wolf aluminum flywheel, we were amazed what we had been missing.
Free-revving in neutral is just silly now. The lighter
flywheel frees horsepower once used for accelerating its 25
pounds. In high gears, the difference is negligible, but in first
and second gear, where each mile per hour means more revolutions of
that 25-pound flywheel, the difference is surprising. Hard-driving
fast shifts are now easier and smoother, but cruising around, revs
actually drop so quickly between shifts that lazy gearwork makes you
drive like a clutch monkey.
The gearbox does indeed make noises now. At idle and
accelerating hard below 2000 rpm, you would think something was wrong
if you didn't know better, but since you put the flywheel in, you
understand the noises. Above 2000 rpm, the gearbox is silent. The
noise shouldn't translate into accelerated wear, by the way, it just
sounds like it does."

Best regards,
Ben Pila (Technical and Sales Support)
Jim Wolf Technology, Inc.

 

I already knew what it was. The point of my post was to mention EXPLICITELY that it was "gear lash noise" and not some arbitrary rattling coming from somewhere in the transmission.


Glad we're on the same page.

 

No harm no foul bro

 

don't feel bad my dealer repaced the throwout bearing and the tranny before they figured out id was normal... that was big $$$$$$$$$$ at least I have a new tranny...

 

I was just thinking about this the other night