so yes I have used the search button...on multiple forums but i can't pinpoint the problem still

So i never had any these weird transmission noises until about 2 days ago.
2005 enthusiast 6sp with 78k miles - popcharger, motordyne plenum, rogue short shifter are the only mods i have (besides rims) and these mods have been on the car for years with no problems.

About 2 days ago i hear this rattling/chattering, sounds much worse then the usual exhaust rattling which i'm use to. It sounds like it's coming from the transmission and it sounds really bad but not really all that loud (bad as in the tranny will die any minute now). I can hear the noise when I idle and at < 3500rpm. I figured that was the flywheel chatter problem that everyone has (although kind of odd it appeared out of no where)

But when i step and release the clutch it makes a fairly loud clacking sound that wasn't there before either. And when i shift fast it doesn't grind but it just sounds and feels bad.

I'm worried because this developed all of a sudden out of no where. Is something busted and i need to replace it or do i just chalk it up to noise "i gotta deal with?"

thanks

 

Hard to say. Bring it to a shop and have it put on a lift to see if you can pinpoint the noise any further

 

If this suddenly developed 2 days ago, something is broken. You will have to inspect the clutch.

 

some more info

car is running fine as far as i can tell, gears don't grind, goes in the same as before, when i slam the gears sometimes it makes a loud sound...not a grinding crunch but some thunk/whacking sound

the sound i'm hearing is like a bunch of rocks rattling inside a hard plastic can...like someone put a bunch of little rocks in the tranny....or even like a blender on low

sound goes away when i press the clutch in, the sound is sometimes a constant rattle but sometimes it rattles then stops then starts again like

rattle...........rattle.....rattle.............rattle etc.

sometimes it's kind of faint and sometimes its pretty loud

 

^^^

 

hmm, so this flywheel chatter thing is something that has to be there from when the car is new? I assume some cars develop this chatter after time? or no?

 

Mine has the same issue. It did chatter when I had replaced the clutch with a STG 4 CC and JWT flywheel but not loud. As of lately and after some hard runs the noise is really loud and even sounds like a bad rod bearing under torque. But it runs fine on the highway and city. Just that ugly noise on take off. I say the tranny is done. Im going to replace mine ASAP with a CD009. I might even go back to the stock flywheel and ACT street clutch.

 

just an update for people doing future searches

I took the car down to the shop and they couldn't pinpoint the problem either. I ended up swapping to a ACT streetlite flywheel and Exedy OEM clutch (was about time they needed to be replaced).

didn't see any problems in the clutch/flywheel area.

After the swap, I still hear the exact same sound...just louder. No other ill effects so far, everything runs/shifts perfectly. So i'm just going to chalk it up to flywheel chatter/gear lashing.

If anything changes i'll update this post.

 

Did you replace the throwout bearing when you installed the new clutch?

 

these transmissions make quite a bit of noise in my experience, but the fact that it seems to have just started making this noise tells me it's not that. could be an input shaft bearing going bad, the behavior would fit. i personally haven't seen a bad input shaft bearing on this trans especially with only 78k on it, but it's not impossible.

 

You mentioned in the OP that shifting "feels bad", I'm assuming you meant you felt roughness in the shifter. Did that improve with the replacement of the clutch?

 

@winchman - when the flywheel and clutch was replaced everything visible looked perfect, the throwout bearing was fine....and i actually had quite a bit of life left on the clutch too

@Nealoc187 - yah i'm still a little concerned but it hasn't gotten worse and mechanically everything seems to run fine so far. I actually took the car to an open track event at Buttonwillow a few weeks ago and everything ran smooth

@PeterSellers - honestly at this point all the noise/feel is a blur. The only really noticeable thing is shifting in to 3rd. And I can't really tell if it's starting to grind slightly (doubt it) or if it's just the louder noise coming from the tranny making it seem like it's crunching a little (more likely).

It's been about 2500 miles now and nothing has improved or gotten worse...and mechanically everything is running perfect. One thing i wanted to try was to switch to a heavier tranny oil to see if it dampens the sound a little. Currently i'm using a Redline MTL + MT-90 mix

 

Switch to NISSAN MTF OEM fluid and see if it helps clean up your shifts and make it buttery smooth. Many who switch to Amsoil, royal purple or other aftermarket oils end up swithcing to NISSAN fluid to help clean up shifts.

 

the gearbox shifts fine, it's just the noise that's bugging me

 

i am having this exact same problem as of 2 days ago? did u switch the tranny fluid? has anything changed? my cars runs and shifts fine but has the same rattling/chattering noise especially loud at 3500 rpm

 

I'm have the same noises, rattle when cluch is depress
I'm gm mechanic for many years and I think is the flyeweeh
when outer balance tha is if you feel vibration around 1800 rpm , but still love my 350z bad *** M LOL