Your center dirve shaft bearing may be the the problem. Mark the position of the the bearing flange on the where it bolts to the frame. White out works well. Then loosen the bolts and run the car with the rear wheels off of the ground. Look to see if the bearing and support are moving back side to side at all. Then re-tighten the bolts and do a test drive.

I had a vibration on mine that was greatly reduced by doing this. easy to try before buying expensive parts

 

Ok thank you. It has been determined but not isolated that it is in the drive line. I will be putting the car in the air this weekend to pinpoint exactly where the vibration is coming from.

 

I will give that a try this weekend. Thank you greatly.

 

I will take a look at that this weekend. It seems that no one wants to take the time to pinpoint the problem, so I will have to do it myself and then tell someone what needs to be fixed.

 

Does it go away in sport mode?

 

Sport mode is only programming in the TCM, I don't think it would have any effect on a vibration at speed

 

No it doesn't. Same vibration. I took it to someone Thursday and he said it was my rear wheel bearings. The previous Jag specialist who sold be a flex disc, that did not solve it, said it wasn't the bearings. So I dropped it off at the dealer last night and hopefully they will tell me some definitive good news that is affordable. Also, now my trans is starting to whine. They will look into that too.

 

I hope I don't need a trans, otherwise I will have to give this one up, maybe.

 

On Wednesday last week a foreign car specialist test drove my car and put it on the lift and said it was my rear wheel bearings that needed to be replaced due to the play in them. To me the play seemed marginal, but he said it was them. He said it would cost about $1,500 to do both sides and at the dealer it would be more. He said it would be better to go to the dealer since they have all the right tools and equipment.

On Thursday night, I took it to the closet Jag dealer who I had in mind all the time. On Friday, the tech said I needed a drive shaft after doing a test drive and certain tests at the shop. I advised the service advisor to order the shaft which would not be in until Tuesday.

Well today I picked it up and FINALLY, THE VIBRATION IS GONE! I also had a noise before when applying the brakes, and that was due to a sticky front left caliper, which they fixed too!

The car drives unbelievably quiet and smooth! They also rebalanced the tires in the process on diagnosing the vibration problem. I will now take my car to this dealer from no on even though they are pricey. In the long run, it will save me time, money and aggravation.

I want to thank everyone who provided input on this problem.

 

Thanks for filling us in on the final result as it will be helpful for those that follow.