I have had my 2004 XJR for 3 years now. It ALWAYS had this minor steering wheel "wobble" so I finally went and bought new upper and lower control arms as well as rotors and pads and did the job.

Take it on the highway the vibe is 100X worse and at 90 I slowly applied the brakes for my exit and felt like the front end was going to destroy itself with vibrations! Scary, I just down shifted and got under 50 and all was good. Will not do this at low speeds at all.

Makes zero sense.

Also noticed when in the air the front wheels will NOT freely spin like the calipers are hung up, again the day before NOTHING but the small wobble was present. Any ideas?

 

I would suspect warped brake rotors as the most likely culprit, especially if the vibration gets worse when the brakes are applied.

 

I would check all of the remaining bushings in the front end. Also double check the new ones in the new control arms. Did you install them your self or have it done. If the rotors are new I would hope they had no runout when installed but the QC is not always what I expect it to be. The calipers could just need to be taken apart and cleaned better with a bit of grease on the "pins/bushings" so that pads slide. The large Brembo brakes on the XJR are about the best to be offered so I would look at the installation as a possible/probable source of the issue. Did the rotors and pads come as a "kit" with replacement hardware? Also did you bed the new pads in when you drove with them? Each brand has their own instructions regarding how to use the new brakes during the first few miles. The different compounds in the pads (semi metallic or ceramic) usually have different procedures. Good luck.

 

ALL NEW loaded arms upper and lower. i have used these many years on customers cars too. BRAND NEW R1 concepts rotors and pads and all pins hardware NEW (Again used for years with 0 issues)

I had a steering wheel wobble when I first got the car. Not enough to really bother with. Rebalanced front wheels and tires (stock rims, Pirellii Pzeros) CUT stock rotors, DID NOT change the wobble or mild braking vibes. I then bought new rims and tires and installed them, SAME wobble at same speeds, MILD vibes when braking, again nothing to complain about.

I then replaced the upper and rear lowers,rotors and pads, SAME WOBBLE but at 70 on, it increased in frequency and when applying brakes it went nuts like the front end was shaking apart.

I can drive normal and no issues even with the wobble (30 mph and up it happens) and you can slowly apply brakes or STOMP them and its like glass. At Highway speeds, terrifying.

So only thing left are hubs? Forward lowers? This one "got me" I have never seen this ever. The only thing I did not replace was the forward lower arms.

I also had ALOT of drag after reinstalling new brakes. Like ABNORMAL drag on both sides. After 20 miles it got "better" but still drags.

 

Did you get an alignment after all that work? This usually helps considering sometimes their might be a very slight change in the geometry of the suspension after replacing several components.

I had a similar issue a while back and ended up replacing upper and lower arms, still had the issue afterwards like you did. Turned out to be the wish bones (front lower). Once I replaced them, it got much better. It'll be hard to see cracks on them, but if they aren't solid, you will feel it when braking because the entire assembly is not secured in place.

You can test if you can see it by having someone drive your Jag for you like 5 mph and hit the brakes; if the wishbones are bad the wheels shift back and then pop back forward, almost like a twitching motion. Try that and also try it while turning the steering wheel.

Once I did this and also replaced the rotted rear tie rods (inner and outer), got an alignment, everything was smooth as butter again. Let us know

 

Did you replace the brake flex hoses? If they start to fail internally they will keep your brakes from releasing fully or, in the end, at all!

 

Alignment is perfect we marked the cam bolts 6 different ways as well as photos. I was suspecting the front lowers. They are SOFT when it's up in the air you can really really move them.

My dad said since you redid the upper and middle lowers then the ONLY thing left is the front lowers or hubs, hubs upon inspection seem fine as well as wheel bearings.

I am going to order front lowers and see. This way the entire front end is replaced. Eric when you had your issue was it a visible wobble at the steering wheel?

 

Yes is was and the steering wheel would shake side to side when braking. If you can feel they are soft, then that's definitely going to improve when you change them.

 

I am ordering front hubs and forward control arms, F it. Ill just replace it all and hope for the best. This car is starting to make me want to hang a for sale sign now.

 

My wobble is ALL the time from 30 mph on.

 

Good topic. Will join to see the results of this saga as I experiencing same wobble on my steering wheel in SV8 today. My front banana-shaped arms are new and more over having new powerflex purple bushes in them from the new. It definitely helped with hard braking stability and transparent feeling of the braking dynamics but nothing did with wobbling of steering wheel on highway. Sometimes I noticed you can eliminate that completely in long right side high speed corners but not in the left ones.

I see upper advice to check brake lines is not bad idea.

 

This is beyond ridiculous that ALL the people on here and searching this out til my fingers bled and NOT ONE person ever followed up (what I could find) with a sure shot cure,lol. How? Why?

 

Called Brembo tech yesterday brake lines will NOT cause a constant steering wheel wobble. So that is out.

 

Hmm.. I have not swapped only front upper arms, to be exactly ball joints as I experimented with PU bushes in them and ended up with factory type once as they squeaked like hell. I was told by everybody including dealer that are wheels particularly rubber. I have new pair of rubber and will put them on soon but I have no confidence it will fix the issue as I have wobbling on both my tire sets (winter R18 less and summer R20s worse). All the rest bushes are new in front and wheels fills very strong in place and no play anywhere when force tested

 

Same here. ALL new loaded upper and middle lowers, rotors, pads, fresh wheel/tire balance it's and it is WORSE. Spoke to an alignment expert locally and he said its worse becaue you replaced all but the banana arms (they are soft) and that the tight new components are pushing that vibe off to the weakest point (banana arms) so I will replace them too. MONEY PIT has started after 3 years of zero issues.

 

Good luck!)) but look on my case i have new bananas even stronger than factory and it doesn't help. Where is mine weakest point then? Upper balljoints? tires? Will change them soon and report back

 

No clue, seems some cars are doomed with this for life, esp since theres 7 pages on it and NOT ONE clear "THIS IS WHAT FIXED IT" which again boggles my mind. I have NEW tires & rims too PERFECTLY balanced. ONLY thing left for me to change is the banana's and the hubs, hubs look fine though. BIZARRE

 

I just find it impossible that there are the many 04-09 XJ/XJR's on here with this issue and NOT ONE has completely cured it? Impossible.

 

SO BIZARRE!! Just came back from doing some laps after re checking EVERYTHING I did up front, re tightened everything etc. I did some HARD ABS Stops then proceeded to drive and WOBBLE was GONE, hit a couple of bumps BAM right back again! W IN THE F!! lol Also had a loud squeal from the left front wheel then when turning slightly right it disappeared?? Thats indicative of a wheel bearing, causing the rotor to be on a different angle because of the wear then when you turn it corrects it. I am just going to order hubs f it. This is so ridiculous.

 

Ball bearings and not roller so they fail at low mileage. Detroit Axle and eBay have them for 80.00/pr.