Vibration through seat and steering

[Jamie_87]

I know there been heaps of vibration posts in the past etc...but mine seems different , i get vibration through steering(u can see the actual s/wheel vibrating if i can hold the car at the speed) and my seat at 20km/h 40km/h 60km/h and 80km/h but smooth as at other speeds ... heres my checklist

tyres unbalancd/miss alignment - cant be cos i got new wheels and tyres and did all that stuff to them

engine-possibly, as when i rev in nutral at about 1750 it vibrates in pulses, same was in vp and mums vt, but still vibrates when driving in nutral at those speeds.

driveline-not centre bearing looks new, all joints are ok, tranny is good real smooth...thinking it might be the tailshaft

i would really love to know what this is because it can get really annoying, and esp being a calais it should be smooth, and being a vs i thought theyn would have fixd this prob as i had same in vp only worse in vp.

also would lowering the car make it worse, cos i no with irs it puts more strain on all the links etc...??

[hako]

I think they call that a "resonant" vibration. The tailshaft can only go out of balance if it had a balance weight attached to it and this has somehow fallen off (will leave a mark where it was welded on) or the universal joint is badly worn (which will be more pronounced when first moving off). Have you switched tyres front to back - despite being balanced! All wheel bearings tight? Engine mounts in good condition - not oil soaked or soft. Plugs and leads not shorting?

[Jamie_87]

tyres are balanced and aligned just got new ones put on - it did the same with my old rims and tyres, plugs r new(2days old), leads are good, not one drop of oil anywhere apart from small weep of bloddy rear main seal,bearings are tight and clean, yeh i thought might have been tailshaft cos that what the prob was with the vp b4...

[sircruisealotVS]

id put my money on it being the tail shaft...
with a slight possibility of it being loose engine mounts...but from what you said it sounds like the tail shaft to me.

[hako]

With the propeller shaft being in 2 pieces with a constant velocity joint, centre bearing and two universal joints I'd reckon it would be something I'd want to visit last!.
No chance that it is some part of the exhaust system touching the body at different times - maybe a stiffer than usual flexible muffler mount.

[Jamie_87]

naa mate , dont think it be exhaust , it feel like the driveline, cos it happens at the exhact speeds no matter which gear im in or what im revving, no1 i no can put there finger on it, they just saying that its a commodore thing, which i would understand cos i havnt been in a commodore that hasnt had this vibration, even my gdad's vx calais has it, not as noticable but its there

[Joey_21]

same thing happened 2 me ended up being cracked engine mounts myne vibrated heaps mostly when i stopped but