I've read a view topics on this, but haven't come across the same issue I'm having.
It's an 06 Coupe...automatic...if I drive contantly at around 50 mph and at 1600 to 1800 RPM's, I notice that after about 10 seconds the shifter starts to vibrate and it kind of feels like the tranny is vibrating as well. If I accelerate or take my foot off the gas then the vibration stops.
Anyone else have this issue? Any guess as to what the cause is and to have the dealer look at it?

thx...

 

I have the same problem but i have an 04 Coupe 6MT!! Let me kno what it is!!

 

It's actually more around 40mph, but ir doesn't happen all the time...weird..

 

i have the same problem and trying to figure out what it is...

i'm getting my 30K service tomorrow.

I have 06 g35 coupe.

i bought it in once to the dealer and they couldn't find out what is wrong w/ it.

i read on the internet that someone tried resetting the ECU, but that didn't help. he also just got the 30K and changed the transmission fluid and that didn't help either...

http://townhall-talk.edmunds.com/direct/view/.f15652f

let me know if you guys find something..

 

You have a 6MT RWD car its normal...

 

I get it to, but being a 6mt rwd isn't the cause. I've had a 92 ZR1 and it never did this. I did hold me back from putting on the underdrive pulley for awhile put just recently put it on, fearing it was a crank balancing issue

 

I found a bulletin on this and wonder if this is the same thing:


Classification: Reference: Date:
AT07-003 ITB07-030 August 16, 2007

2006–2007 INFINITI G35; SHUDDER AT 40 MPH

The vehicle has a shudder when the transmission is at operating temperature and the torque converter is:
• Engaging lock-up in 5th gear (light acceleration at 40 mph)
• Releasing the lock-up in 5th gear (coasting at about 40 mph)
NOTE: CONSULT-II (2006 models) or CONSULT-III (2007 models) can be used to confirm
transmission gear position and lock-up condition.


It goes on to state that the transmission valve body (control valve assembly) should be replaced....

 

i saw that bulletin a while ago.. took it in... but you still have to prove it to them... take them out on a test-drive and show that the shuttering does happen...

after i proved it to them...

they changed the valve body and now the shuttering is completely gone...

strange thing is .. when i showed them the bulletin.. they originally just dismissed it and said it was fake.. they didn't even check that it came from the actual infinite site.. they said they never changed a valve body before...

 

You need a new Flux capacitor!