R33 Gtr Vspec -vibration/shudder Coming From Rear Over 110kph

[FLYSKY33-Brinne]

Vibration and shudder coming from rear only in 5th gear

starts and seems worse at about 2800-3000rpm (110-120kmh)

Most noticable on moderate throttle, just before boost comes on, its hard to tell if its there when boost comes on since the engine gets a bit noisier but on hard acceleration it smoothens out..

Same speed or same RPM in 4th gear is fine, smooth as.... only 5th gear

any help would be much appreciated..!!

FYI- i have brand new tyres put on 2 weeks ago, Done a wheel alighnment with rear camber adjusted and front toe adjusted, also done wheel balancing twice on all four wheels as the first time they didnt do it properly..

the second wheel balance the guy said 3 of my wheels (Front left, and 2 rears) are buckled..not sure if this could be the cause of vibration but i do know that this is why my steering wheel vibrates..

Wheels are 18 x10.5 all round with them wrapped in 265 35's..

Thanks in advance..

B

[Moodles2]

Is the tail end sliding out ever so slightly during the vibration/shudder, if so could be HICAS related.

[gach2]

your wheels being buckled would have no reason for it to shudder in 5TH GEAR ONLY

if it was your wheels it would shudder on any gear at a certain speed

on another note you shouldnt be driving on buckled wheels

especially at 110kmph

ill be honest and not put the heat on you about that

i have done the same but have been careful and the max speed i was on was around 60kmph

[FLYSKY33-Brinne]

Moodles2- Nah Tail isnt sliding out at all.. I disconnected Hicas but removing all the plugs around the diff anyway..

Gach2- Good point..but only happened recently so not driving it as much as i should..and stupid potholes near city is what caused it, trying to get a hold of council to pay damages..!

[GTR-N1]

Stay steady on 110 and see if shudder is quite pronounced.

Then accelerate and/or decelerate and see if it disappears whilst still in 5th.

Then try and see if it shudders again at a steady 120 or 100.

If so, get the car up on a hoist and check the joint in the middle of the tailshaft and see if it's weak.

[FLYSKY33-Brinne]

Terry, appolagies for the delay.. was on holidays for a while...

Stay steady on 110 and see if shudder is quite pronounced.- yes it is pronounced..

Then accelerate and/or decelerate and see if it disappears whilst still in 5th. -seems better when i accelerate (goes away) - however when i deccelerate from 110 its still there, also when i put in 4th gear noise goes away..

Then try and see if it shudders again at a steady 120 or 100. - yes it does.

Im leaning towards oil/HICAS as yesterday HICAS light came on while on the freeway but then turned off when car switched off...

any advice is appreciated.

Thanks.