Vibration through the steering wheel

[alanXK8]

Hi to everyone reading this. I am new to Jaguar ownership having previously owned a load of other cars including a number of BMW coupe's (now nobody will speak to me).
I have bought a 2001 XK8 convertible with 28k on the clock and full Jaguar history. The car is in excellent shape (Mistrale blue with Oatmeal interior and 18" Milan wheels) but I am not happy with the steering. It is extremely light (which I believe is a characteristic of these) but also seems to transmit a lot of road "patter" through to the steering wheel. The feeling is rather like the vibration you get from out of balance wheels but the car has brand new P Zeros on the front and the balancing has now been checked 3 times (including my local Jag agent - Swain and Jones of Farnham, and Racing Green). The alignment was also checked previously.
The amount of vibration varies with the road service and on billiard table roads pretty much disappears. The car has been up on the ramp twice to check steering and suspension joints, discs and calipers but neither specialist has found anything amiss.
I tried a couple of other XKs before buying this one and I do recall that they showed a bit of wheel wobble as well, but I think mine is a bit worse. Is this something I have to learn to live with (including a bit of scuttle shake through the footboards when going over bumpy roads), or can anyone suggest where I look next?
A mechanic friend has suggested replacing the steering UJ as he found that did the trick on a couple of XJSs that had been standing for some while and allowed the UJ to sieze a bit.
Any advice or comments please. Is there an owner near me who I could visit to see if there is much difference betwen their car and mine?

[GrandTourer]

Hello Alan, welcome to the forum.
Regrettably, I don't live close enough to you to consider meeting up and compare cars, I live in Leicester. I would have been happy to do so otherwise.
I don't have any specific answers to all your questions; just wanted to say hello and hope other members can help.
Mine is an XK8, MY2000 Coupe, factory fitted with the Super Sports Suspension and also CATS. I do find a feeling of judder sometimes going over really bad road surfaces (my suspension feels quite stiff to me anyway) and myself, and others, get the tram-lining feeli through the steering wheel. That, I think has more to do with tyre width and tyre pressures.

Hope you get answers. Good luck

[gasman1003]

These cars can suffer from poor wheel balancing and can be tricky to adjust for the average tyre centre.

Try Racing Green Cars in Ash Vale (near you I think) and ask for Chas Whitaker.

http://www.racinggreencars.com/

They are a fount of knowledge and have all the right equipment for diagnosis and adjustment.

I travel from the Wirral to see them.

Good luck with the car, you will fall in love with it and never want another BM

Steve.

[Sharfrs2]

Sounds like your wishbone bushes need replacing as well as getting the wheels balanced correctly. Mine was like that until I had them done, now she drives like a different car.

[alanXK8]

Well, never thought I would get such quick replies so thanks to the 3 of you who (so far) have taken the trouble to comment.

To "Gasman", I've already been to Racing Green and whilst they were helpful, and balanced all 4wheels, this hasn't eliminated the problem. They are also quite expensive aren't they, but they did suggest doing their steering modification which apparently adds more weight to the steering. It costs about £300 but seems worth considering. Has anyone had that done and if so, what were the results like? I thought it might help dampen out the "kickback" I seem to get from the road surface.

To "sharfs2", Racing Green did in fact detect a slight distortion ion one of the upper wishbone bushes. It seemed such a minute thing that I had rather discounted it, but maybe I should think again.

To "Grand Tourer", thanks for the interest and your comments on tram lining. I did wonder about the CATS system (and indeed about going for the XKR rather than the XK8), but for my style of motoring I didn't feel it was worth holding out for, so I bought the nicest one I could find in my price range. Interesting that you find the suspension a bit stiff . I think I will try taking a few pounds off the tyre pressures to about 28 and see if that makes a difference.

Interesting that nobody else thought of the steering UJs as a possible source of the problem. Does anyone have any thoughts on that?

Hope to see you all at some kind of JAG event. I'm thinking of going to one of the two "National" Days ( at Harewood House or Littlecote).

Best wishes to all , Alan

PS I may get my short article on buying the XK8 in Classsic Cars in the next couple of months. Here's hoping!

[mike020150]

Hi Alan, I agree with everyone else! Your car's problem could be any of the suggested issues. Wheel bearings are another common failing from around 30K onwards, albeit I asume you will have checked them already. Don't forget that unlike older Jaguars, there should be no endfloat in them. I note that yours is a low mileage car which could have something to do with the problem and would make brakes my most likely candidates. Low mileage can lead to sticking calipers and/or distorted discs, particularly if the fluid has not been changed as it should have been. I would check the calipers carefully for smooth action and by peeling back the piston covers to check for telltale signs of rust as well as checking disc run-out (max 0.1mm front, 0.15mm rear). When you solve the problem, I guarantee you won't be able to get the smile off your face every time you drive the car. XK8s are wonderful machines to drive, exciting yet smooth and relaxing in a way that BMWs don't manage to capture. Good luck! Mike.

[GrandTourer]

Alan,
I don't think the stiff feel of my suspension has anything to do with CATS, but with the Super Sports Suspension option which has nothing to do with CATS.
I also used to use the 'Comfort tyre pressure' of 28 front and 30 rear. But, I do mostly use 30/32 respectively nowadays.
Only when I go to the Continent touring, higher speeds in Germany, do I go for the higher recommended tyre pressure of 32/34.

[jagnut]

I have detroit alloys on my XKr, which i was worried would cause vibration at speed. However if you make sure the pressures are correct then take them to a decent tyre outfit and make sure they are balanced when they are hot this should rectify the problem

[alanXK8]

Many thanks to all of you who have replied to this topic, you might be interested in this update.

After taking the car to 3 known Jaguar specialists, the last of them removed the steering column to check the UJs but found no wear. They then replaced the lower mount bushes for the front shock absorbers and then the upper wishbone mounts (both sides). They found nothing else amiss having checked out wheel bearings, brakes and all the other steering and suspension joints.They then proclaimed the problem solved..., but it was still not entirely to my satisfaction.

I then took the car to HA Fox at Guildford for yet another opinion. Almost immediately their service manager diagnosed nothing more than scuttle shake, which he said is endemic in these cars, but far less so than the XJS which preceded it. He also said that virtually all convertibles suffer from it to a greater or lesser extent, even the new XK8. He also commented that actually my car drove very well, which was encouraging from a man with lots of experience. This view was confirmed by one of their salesmen who has driven a lot of XK8/XKRs.

So. there you go. The car actually drives beautifully in all other respect but still has this tendency to reflect a poor or uneven road surface as a tremor through the steering wheel. I think this characteristic is more noticeable because the car is so very smooth in all other respects, I guess I'll just live with it!

I shall be going to Harewood next Sunday so hope to meet you all. By the way. take a look in this month's "classic car" magazine because my car is featured on P.27.

See you guys soon!

Alan