At around 40 mph, our 06 Cayenne S begins to make a vibration shake that you can feel under the arm rest. Feels like its under the car and somewhere in the middle. 40 mph it starts and ends about 60 mph.

Anyone know what this may be?

 

Cardan(Drive) shaft?

 

I am thinking drive shaft as well. Have not gotten it on a lift yet to inspect. Any known issues with these? Car has 94,000 miles.

 

very well known issue- just search here for cardon shaft! in fact just ordered my new parts last night because my at 87000 my is vibrating too- good luck!

 

read the stickys, you find all the info for whats gonna go wrong, including your cardan shaft bushing.

 

I agree with the others - it sounds like the cardan shaft.

 

Cardan shaft vibration usually doesn't end at higher speeds. It gets worse. You should check front wheel lower control arm bushings.

 

Rear tire out of balance?

 

A wheel imbalance will be felt in the steering wheel and through the floor and seat. If you feel it through the armrest, its almost certainly the Carden shaft bearing. It can be quickly diagnosed by a mechanic. Get it checked; if it fails, you'll need a tow truck.

 

Mine is beginning to vibrate. I am going to try the one piece driveshaft from Lindsey Racing.
http://www.lindseyracing.com/LR/Parts/955AXLE.html

 

I thought maybe only front wheel imbalance will be felt in the steering wheel?

 

Cardan issues usually occur during acceleration or deceleration not at a specific speed. Look at your lower control arm bushings. Could be several things.

 

On level ground, even at higher speeds under a light load the Cardan shaft can smooth out quite a bit. It is usually under higher Torque loads that the vibration occurs.

 

Thanks to everyone who replied. Great folks here. Now it's research time for what kind of job the fix is. Whether it is a dealer fix or something I can manage safely through. Thanks again folks.

 

Cardan shaft or control arms....you can do both yourself. Few skills necessary!