I stumbled across this about the XKs. My VDP does this too. I thought it may have to do with my 50mph vibration as far as a failing part. Is this a common complaint of the X350 too? I think mine has always done it since I got the car almost 2 years ago.

https://www.jaguarforums.com/forum/x...judder-142498/

 

Mine has always done it, I think there is an additive for the steering fluid, I just got use to it.

 

The additive cures the squeaking sound that comes from a steering rack seal and is transmitted up the steering column. It worked on our '04 XJR. I believe the judder is caused by a different issue as discussed in the thread for which Torrid posted the link.

Torrid, has the judder improved or changed since you tightened the steering rack bolts?

I'm attaching the TSB about the additive.

Cheers,

Don

 

There's an ever so slight hint of it still, but before tightening the steering rack bolts it was so jarring that the feeling could be felt through the whole chassis. It only does it if the car is completely stationary when turning. If I'm even slightly moving it doesn't do it.

 

I have had this squeaking noise on both of my XJs. The relevant additive was added to the power steering tank (there is a code stamped on) 5 or 6 years ago and no problem since then!
Mind you each car has at the tune of about 400k km each