I have been chasing a shimmy in my 03 XJ8 since I got it in April 2012. As I've mentioned before, I've had the wheels balanced several times but I can't get rid of the shaking. I noticed the other day that my left rear tire was about shot! I replaced it with my like-new spare and all shaking is gone -- I'm talking ALL shaking is GONE. I used to have the shaking at 60mph and some other speeds as well, but after driving 60 miles on highways today, I didn't notice any shaking. I'll be driving 1,500 miles starting tomorrow and ending on Wednesday. I will be inspecting the wheel I took off and might have someone look at the tire as well, just to see if either of those things was the problem.

On another note -- when I carefully popped the center cap out of the wheel, one of the tabs broke off! This isn't the first time this happened - how annoying is that?

 

Very, very, so much so that I bought a spare car in order to have replacements on hand.

Re your tyre, you will probably say no way, but could it ever have been curbed/potholed?

Even of nothing is visible, this can cause an internal rupture, which can lead to all sorts of later weirdness.

 

I don't ever remember "curbing" the left rear tire, but I'm sure I've hit some good potholes!

 

I had a vibration that could not be cured by balancing. Putting it on the Hunter road force balancer identified a defective tire.

 

I'll know more after my 1,500 mile trip that starts tomorrow.

BTW I used some double sided tape and wedged the center cap in nice and tight. Hope it stays like that for the ride back to FL. I don't think it's good to drive without it. I'll keep my fingers crossed.

 

Just another thought -- changing the tire on this car (2003 XJ8) was easier than almost any other car I've changed a tire on. The ratcheting lever that is used to jack up the car is so easy to use, and the jack points are so easy to find -- just pop out the rubber stopper and insert the jack! The extension on the lug nut wrench is a nice touch, too! I dreaded having to use the jack from the trunk, have had some bad experiences with getting it out and trying to figure out how to use it, but this time it was so easy.

 

How do the rest of it's 'boots' look? good, even tread depth across them?

 

The other tires are in fine shape -- I replaced the right rear tire several months ago because I drove it too far with too little air! The front tires are in great shape. When I replaced the one tire, I asked a couple guys at tire shops if they thought I needed to replace the other tires and they both said no. All of my tires had the correct tire pressure until the left rear started losing air. In other words, the wear on the left rear tire wasn't due to low air pressure.

 

Most likely the tire: the balancing would have caught a bent wheel (which I think is my problem).

 

I drove 1,500 miles in the last two days and the shaking is so slight that I'm willing to say it was the tire or wheel.

BTW is there a way to tell how old a tire is by the numbers on the sidewall? I think I'll google that....just want to see how old my spare is!

Well, if my research is correct, the spare that I put on my car for this long trip was manufactured in 2001 -- should I be concerned? LOL Kind of too late to be concerned! I do plan to replace it with one that matches the other three tires.

 

The usual guideline on tire manufacturer sites like Yokohama and Michelin is to scrap tires 7 years or older regardless of mileage.

 

I've heard/read that some people say four years.