Strange Vibration In Trans... 6Sp Man

[alex.a]

hey guys

Recently bought v35 coupe and having a few dramas.

its a 6sp manual and has had a button clutch/lightened flywheel fitted. now im stressing about the transmission as when you first take off (release clutch, load up trasnmission) the gearbox makes this weird vibration/pulsing/deep knocking noise... really noticable through the gear knob (rattles badly). the vibration happens with engine rpm increase... follows it perfectly, definatly something spinning too.

it wont do it on deceleration, nor in netural (with clutch in or out) and i even jacked the rear of the car up, placed in gear and let the wheels spin in the air.... no noise/vibration, so must need load on the driveline.

the engines runs freely, no knocks or noises and the trans shifts smoothly... just the horrid vibration.

i have read plenty of info regarding removing the stock duel-mass flywheel and replacing with a lightened unit creating lots of noises and transfering vibrtions.. but i just cant see this being normal!!

has anyone else out there exprienced something like this?

the only possible things i could think of are

-damaged spigiot bearing?

-worn bearings in trans

-damages imput shaft

-incorrectly fitted clutch/flywheel (but think it would always make noise then)

-excessive lash between gear sets?

-shifter flogged out and just ratteling around with engine rpm (thinking it may be a short-shift kit, very short shifts.. never seen stock to compare)

-worn diff bushes, allowing the diff to move under heavy load, thus moving the tailshaft a tiny bit out of whack?...(prob stupid but taking a stab in the dark)

if anyone can shed some light on the situation i would greatly appreciate it..

sorry if this post is hard to understand, its hard to try and explain the problem. im going to record a vid and upload so you can hear the problem.

thanks guys, alex

[..350GT8..]

hey

check your driveshafts.. and try to find out if one side of the car vibrates more.. i.e. the driver side or passenger side vibrates more... let me know how u go..

goodluck

[alex.a]

found out it was my clutch causing the issues... replaced with a custom npc and she is perfect now!!!

[mutex]

I'm bringing this back from the dead, hoping someone may be able to help.

I have a recent purchase 2004 v35 sedan 6mt with the load vibration/knock/rattle noise on acceleration but not cruise or deceleration in all rpm/all gears.

I replaced the oem dmf clutch with a locally sourced exedy uprated clutch/npc smf kit - NSK-7454SMF, I use Castrol VMX-M 75W-85 transmission fluid.

The first clutch install was botched by a local gtr specialist workshop (it made the noise then), a new clutch was fitted along with my dad/I replacing the important input and output shaft bearings in the CD008 gearbox before reinstallation by another workshop.

After the new clutch install I still have the same acceleration vibration as before.

The pedals/gear knob vibrate badly with the accompanying rattle/knocking noise.

I took the car to a car importer familiar with v35s and he said it was normal for the CD008, and that the CD009 was as better transmission.

I have listened to videos and don't believe it's rod knock or knock from bad fuel, the diff bush is flogged so will be replacing that soon.

Any ideas or 350z/v35 experts in melbourne who may be able to help diagnose please let me know.

 

 

 

 

 

[sonicii]

Not normal for any V35 6MT..  only difference on the CD009 was improved multicone synchos.

Have you checked engine mounts/transmission mount, diff mounts?

How did the first workshop 'botch' the clutch install?  did they possibly cause some damage which is causing the fault and it hasn't been fixed?

[mutex]

The problem was there after the botched clutch install and now after new clutch install. 

The second workshop checked only trans mount, but I'll check all mounts.

I suspect the exedy clutch kit wasn't balanced, but lets see if the mounts are ok.

Interesting that an importer (not the importer of the car) said it's normal, hmm, pretty rough compared with my long throw vibration-free r34 gearbox.

 

 

[sonicii]

If it was normal, it would have been there before the first clutch install.

One of my pet hates is car dealers and sometimes mechanics saying 'they all do that, it is normal'..