I have a 2004 XJR with 97k on it. I have had it since 50k. I had to do a trans service due to a pan leak, where I replaced the pan/filter and the elec connector sealing sleeve. Job went without a hitch but when I took it out for a test drive I have a buzz harmonic type vibration from about 30 mph and up. I shift it into neutral and no change. I turn the wheels and apply the brakes and get no change other than a small difference as I scrub off speed. If it is transmission related then it would be tail shaft as engine rpm has no effect. First I am trying to rule out trannsmission but since that is all I touched then I am starting there. I am **** about lift points but in the process of getting it 22" off the ground on jack stands, could I have tweaked the body to touch the driveshaft or cause the center (carrier) bearing to be out of line?... or something like that? Also The frequency seems way too high to be tire related.

Any help would be appreciated.

Thanks

 

OK, some experienced Jaguar mechanics can straightaway deduce what is happening, but sometimes, it is necessary to get the car onto a rolling orad, and spin up the fronts first, then the rears to determine which end is causing the trouble.

 

I have read this site since doing the research to buy the car... about 2.5 years. I usually am able to find existing thread that gets me down the road but I decided to join because of this problem. It does not transmit through the steering wheel so I have not considered front end as a possibility. It also does not pulsate but is quite linear with speed. It is not violent but is distinctly through the body. I do hope one of the techs has witnessed it and can tell me something that is EASY to fix.

Thanks

 

First off, have you checked for damaged or badly worn tyres and damaged wheels ? How long have the tyres been on, and are they reputable makes or Jo NoName ? Always do the simple and cheap stuff first !!

 

The tires are worn, and so I will have them checked for the sake of being diligent. If it is tires then it would be a change of state while the car was on jacks for a day and a half. They are Yokohama Advan S4. Let me see how that turns out.

 

Just had a look around and found this:

Jaguar XF New XK X350 XJ S-Type front lower diff differential insulator C2C16377 | eBay

An insulator-could be a vibration insulator.

Have a look at pics of the x350 diff on these pages-there appears to be a stabiliser on it.

Also the x type has a vibration damper!

A few ideas for you?

Just trying to help and learn at the same time!

 

Diff or drive shaft is what I am leaning toward, but I am going to try to get the tires looked at Sat.

Thanks

 

TADTs. Yup mine has had a driveline vibe since new. Minor but... I knew to fix it would open a can of worms.... 8 yrs later car throws a code for a loose intake tube... besides that still perfect. I just ignore it

 

OK New tires today and no change in sound so I am going to be forced to say diff or drive shaft. I jacked up the rear of the car and ran it up to 60 mph and got no sound, but 2 problems with that is only one wheel spins and 2, no load so that may be telling me nothing. Any thoughts?

 

Yeap sounds like a carriers bearing,for the axle..Get under the car,while raised,on the differential side near the boot,try shaking the axle to see if you have any play...You should have some sway,shake up and down and front and back.The good side should be firm and the other should be lose.I could be wrong,but saw this happen on a xj8 before.

 

I had my front end guy at Sal's drive it and he nailed it as passenger side front wheel bearing. I cannot remember replacing a wheel bearing since the early 80's. but that's what it was bigger than life. Thanks for the help guys.