Shaking at speed
 

Having acquired my XK-8 this week I did notice some shaking which I chalked up to my tires being out of balance. I got them balanced and I still noticed some shaking. What's the next candidate that I should be looking at? Suggestions?

Are they factory Jaguar wheels? And at what speed does the shaking occur? And please list your year and model in your signature.

It is a 1998 XK-8 with Jaguar factory wheels. The shaking occurs approaching 70mph.

Check for worn suspension parts.
My '97 is pretty stable at 70.

Do you feel it in the steering wheel or your butt. How is the wear of the tires.

Does it get worse above 70 or settle down? If it gets worse, I would suspect a tire or worn suspension bushings or a bent wheel.

Forgive the pithy nature of my original inquiry, I was at work and pressed for time. I think you may be right GT, I suspect a tire even though I had them balanced yesterday. Even though the tread is quite good it may be a separated ply starting to go. It's fine until about 62mph and by 70mph it is at its worst. It seems to lessen after 70mph but I need to double-check this. Even though I paid for balancing already I may have to bite the bullet and have it checked again by a different technician. Damn.

Now that I've had time to think I believe I have a plan. If one of the tires is bad, perhaps separating, I'll switch out the tires one by one with the spare. If there is major improvement after one particular tire I'll know I nailed the problem. Now let's hope that spare is balanced...

could a rim be BENT? The shop that balanced the tire may have done the best they could and did not tell you?

Good question BRG.

I had the same issue approx 62 to 70. Seemed to get better for a while and then worse. Finally one front tire went flat. When I got it replaced, the shake was gone.

Budda,
This seems to be the most likely thing to me as well. So didn't the guy who balanced my tires yesterday notice this? I do wonder. Like I said earlier it may be that a ply is separating and it just isn't visible yet. The shake is rather noticible as my rear view mirror vibrates intensely and your right foot can really feel the shake near the accelerator pedal. Either a front rim or tire is out of whack.

I'm coming back to this finally after much investigation and diagnosis. The lower ball joints have already been replaced so the big job now is to replace the control arm bushings which are loose on the passenger side and probably not too far behind on the other. While the wheels are off I'm replacing the front rotors with drilled, vented and slotted ones along with ceramic pads. The shaking should be remedied by the new bushings and that rotational unevenness in the brakes should be eliminated while I'm at it. I plan to do this on Monday morning so wish me luck.

Americain,

I wish you well with this. I have used both stock and urethane upper inboard bushings and prefer the urethane parts.

Mike

I had to have my XK8 balanced with the Hunter road force machine. Even then, there was one wheel that passed the test but caused a vibration. I think the holes for the bolts were not concentric with the center bore and I finally replaced the wheel.

Check the inner tie rods with everything apart. They are very easy to swap out, and if you do one side at a time, its very easy to realign the car with string and adjust/test drive until the steering wheel was perfectly straight.

My inners allowed for a lot of uncontrolled wheel movement that could potentially drive steering wheel movement.

I've always found that a good stiff MAITAI takes care of my "shacking at speed"!:icon_drink::icon_couchhide:

OK guys, I'm having difficulty with the big long bolt that holds the upper A-arm. The nut at the south end came off as planned but the bolt itself won't budge at all even with the nut removed and with me attempting to unscrew it from the front with a very long wrench attached to a pipe for extra leverage. The bolt should be free to rotate with the bushing but it doesn't move at all. Even with the pipe extension it wouldn't move a bit. I sprayed some penetrating oil all over it and called it a night. Any suggestions?

P.S. I've seen other posts about this here at the forums and the standard operating procedure seems to be to use as must penetrating oil as possible and keep trying to get it to move. Onward.

Yelp, that's the worst nightmare trying to get the pivot bolt out when it's seized in the bushing sleves. Some have had to cut it in two pc's to remove, good luck, there's not easy answer.

Jandreu's right, don't waste any more time on them, just cut them off and replace with second hand bolts.


The bolt remnants can then be used to refit the top arms and shims before pushing though the pivot bolt.


https://www.jaguarforums.com/forum/a...ine=1363127376
https://www.jaguarforums.com/forum/a...ine=1363127376
https://www.jaguarforums.com/forum/a...ine=1363127376