I know this is quite a covered topic but for some reason over the past week my x type has developed a strange shake/judder etc.. at 45mph precisely. Anything below or above it is fine. I have tried selecting one of the hold auto selections i.e2,3 or 4 and it still shakes at the same speed so I can rule out engine problems, so my last choice is either maybe propshaft out of balance or possibly tyres but am unsure. I did have the dreaded propshaft squeek/howl but this dissapeared after lubricating with lithium grease the centre bearing. Does anybody have any suggestions as to what I should now check? Any help would be most appreciated. Thankyou.

 

Stumpy, first, rotate the tires front to back and vice versa. Is the shake still there? If yes, then I would be looking at the propeller shaft bearing. If the shake went away, then you have a tire/rim issue. If it is a tire/rim issue, rotate the tires back only on 1 side. Did the shaking return? If yes, then the side that you changed, that front tire is messed up some how, take it to a tire shop and they will be able to diagnose whether it is a bad tire or a bent rim. If the shaking did not return, then it is on the side you did not rotate the tires on.

You may want to also do a quick check of the front tie rod ends to make sure that they are tight. Normally they offer up vibrations over a wider range and at various speeds. But, it is possible that it is a problem. you can do this as you rotate the tires.

 

Once the car reaches 45 and it shakes does it stay the same at higher speeds or change in any way after 45 and immediately end once it gets below 45?

 

You may have one of serval things with the tires..

1. Threw a weight

2. Bent wheel

3. Belt seperation

4. A tire out of round.

 

Make sure your lug nuts are tight. My last car once shook up to 50 and then stoped just like you were saying. I thought it was the strangest thing until the tire passed me while i was driving.

 

Problem now solved. Thanks all for your comments on what it might be. Thermo was spot on with the centre bearing on the propshaft.
I have now had the propshaft replaced and it is now a fantastically smooth ride! Just a word of warning to those with the howling propshaft:Although greasing the centre bearing will help for a period of time just be prepared for the eventual demise of the centre bearing.
In the end it became nearly impossible to drive the car with a very bad rumble/shake but only between 40 and 50mph.