I've posted previously in regard to my XKR having a vibration issue and thought I would re-post having now found the problem after much work and hassle along the way.

So eventually after many checks and replacing bushes on the suspension, having the wheels balanced to the car etc...etc....

I had a Hunter Roadforce machine report on them which showed one of the fronts as 225N and one of the rears as 125N, I'm not sure what this means apart from that the tyres failed (I've attached the reports for reference).

Apparently the limit is around 60N.

Tyres are Avon ZZ3's

So spoke to Avon and they have been helpful and agreed to send a set of tyres to be re-fitted, hopefully this will correct it finally.

Anyway for anyone out there with a vibration problem the Hunter Roadforce certainly seems like a test to have done on the tyres, even at £25 per wheel.

I'll post again once Avon come back to me with a delivery date and if it solves the issue.

 

Your attached reports make interesting reading.

Good thing Avon stepped up. I guess the reports were pretty good proof of the problem.

 

Thanks Esh, good post that I'm sure others will find helpful

 

That Hunter wheel balancer is a required tool for Jaguar dealers here in the US.

 

Eventually Avon sent replacement tyres and they have been fitted, I drove away with high expectations and 95% of the vibration had gone, the other 5% was a rebalance because the idiots only balanced with weights on the inner side of the wheel.

The "N" measurement on the reports from my original post relate to the Newton force given by the radial run out of the tyres, ie how out of round they are.

This really does prove the value of the Hunter balancing because the wheels can be in balance but still have a radial run out which you can only find on a Hunter machine.

BUT not quite the end of my 8 months finding the problem because the bloody idiots at the garage despite me telling them to remove the rims before taking the tyres off because they are so delicate...did they ...NO so result all four chrome rims on my BBS wheels now have the three prong marks from the tyre machine......

To be fair the garage ordered a new set for me (you can imagine they were not exactly happy about it) and I've had a call today to say that they have arrived.

I've decided to fit them myself because I really don't want any more problems and I prefer to spend a day relaxing in the garage doing them properly and know that there is silicon round them etc....

So a long journey , lots of new parts, ie from wishbone bushes, upper and lower, rear aswell and other work which I'm sure contributed to the vibration but the actual problem was the tyres.

Total cost to sort everything well, I originally started out with a new set of BBS wheels and tyres which were £2500 and spent a further £1100 on work trying to sort out the vibration.

Luckily, Avon (Cooper) tyres where superb and I didn't have cost for the replacement tyres nor the rims which I now need to collect and fit.

rgds Esh