Was in a shop today getting an alignment done, and the ongoing driveshaft buzz issue came up. The tech said they had solved a fleet wide driveshaft vibration on a particular new model by unbolting the shaft from the transmission, then rotating the holes in the flange clockwise to the next bolt in sequence, and then re-attaching the shaft. Sort of a field rebalancing.

What do you guys think? Ever heard of this before? Worth a try?

 

Skid;

I had a huge problem with noise from the drive linkages in the V70R AWD last year.

After one dealer shop incorrectly replaced first the steering rack and then the bevel gear of the front end, four wheel drive, the noise was not only still there but worse, no refund after a shouting match about thievery, five minutes after I had paid and test driven the car.

Resisting the urge to "accidentally" back through the show room window because of "steering problems" I went straight to another dealer who promptly put the car up on a side lift and started the car to drive the wheels and immediately identified the problem as a drive shaft.

My point is do that first, there are several things that can cause a driving buzz even on two wheel drive, before you go to the expense/trouble of rotating a drive shaft to confirm that is actually the cause of the noise, cheap and easy to do.

If that is the problem then you can try the quarter turn drive shaft rotation trick and repeat the side lift "test drive" to confirm if it worked without ever leaving the shop or risking more damage to the car if that is not the solution.

Or you could just trade it for an XKR and have some 'real' fun.

(Sorry no pics on a car site, but thanks for the interest....you will just have to trust me on this one...)


cheers,

jj

If confirmed as a drive shaft issue

 

My first question that comes to mind is-
Has your drive shaft been removed so you might suspect it was re-installed in the wrong "clocking position" ? (I've just done too many repairs for "spontaneous unbalance" that didn't get me anywhere. )

I'm also hearing a buzzing sound at around 1900 rpm but it's only under heavy load such as climbing a hill or accelerating. That would be tough to test on a lift. This is why I leave it in sport mode most of the time. In sport mode it doesn't lug the engine enough to get into the buzzing mode. I would suspect an engine mount but it seems to be coming from the back.

Mike
(Just a couple of thoughts...)

 

It can come from the differential as well.

Buzzing from drive shafts is more common with longer driveshafts and with a dependend rear axle where the diff and drive shaft are moving. Not the case with the xk8/r

 

I've been up on the lift with it a few times, making the noise for the shop techs underneath. We even took the shaft out and lubed the slip joint. Noise was greatly reduced for a couple of days but has returned in full force.

 

How sure are you that the noise is from the drive shaft?

 

I submitted a post about a week ago asking the "collective minds" of the forum to help solve my problem. My description wasn't so good but a drive shaft buzz sounds like I may have the same issue.

My "buzz" shows up around 40-45 MPH under a light acceleration. My mechanic has searched and searched and sees no evidence of any problems.

I'm very interested in following this thread!

Best regards,
Scott

 

After we took it out of the car I took it to a couple of drive shaft rebuild shops and listened to it as it spun on the balancer. Noticable knocking sounds coming from inside, which were also heard under the car when on the lift. I think the buzzing heard inside the car is a harmonic reaction to the knocking inside the shaft, caused by a loose slip joint.

 

Does the noise go away when you put the car in sport mode? If you are not sure give it a try.

 

No, I drive it in sport mode all the time. I don't like granny mode, the tranny won't downshift if I hit the throttle which makes the engine bog down.

One thing about the buzz it that if it starts buzzing and I shift it into neutral and get off the throttle, it will keep buzzing as it slows down until the car stops. That's got to be a clue about what the problem is, but I can't figure it out.

 

Keep in mind that your transmission is still connected and rotating when in neutral or in drive. If you had looked at the drive shaft and all was good I would look at the output bearing of the trans and the input bearing of the rearend. Do you have a place to get it in the air with the engine running and in gear? If so see if you can use a stethoscope and pinpoint the noise. Keep in mind that it is running with no load, if you do that you could have someone apply the brake to simulate load as you make your check. Use caution when doing this wheels and driveshaft will be spinning and have no mercy.

 

FYI Gus means use a mechanic's stethoscope with a long metal needle to precisely locate sounds instead of a medical stethoscope which has an amplifier disc and would be dangerous for your hearing to use on an engine.

Good luck and let us know when you figure it out.

cheers,

jj

 

This might help Mechanic's Stethoscope - Harbor Freight Tools

 

Thanks Gus;

My father was using those 50 years ago to great effect and his customers surprised delight.

"The Car Doctor".

That is so cheap I am going order one for myself....never know when you might need to diagnose a 'patient'.

PS to Skid let the mechanic check it....have seen and heard of too many cars falling off of lifts to really enjoy getting under them....no offense Gus.

cheers,

jj

 

I am with you on the lift. I guess I did not make myself clear. Using jack stands is a good safety measure but not ideal for work under the car. Not long ago I read a post on another forum where the wife came home to find her husband pinned under the car dead. He was working with just a jack and it leaked down. Jack stands are a good safety tool and should have been used but not one for me to work under. Your safety is not to be taken lightly!

 

Whenever I lift the car at home I place the jackstands snug underneath and leave the floor jack in place for redundancy. Jackstands come into play only if the floorjack fails.

I run the car for diagnostics only when it's on a lift in a shop, never at home.

 

Skid;

Good Man, glad to hear it because I enjoy your posts.

cheers,

jj

 

Thanks JJ, hope to be around a long time lol. I'm going up on another lift at a transmission shop this afternoon at the request of the warranty company. I agree with Gus that the rear bearing in the tranny is a suspect.

 

Skid;

You sure you don't want to just upgrade to an XKR?

Find Your Car: Jaguar XKR Listings Near Santa Fe, NM 87501 - AutoTrader.com

Skip to the featured listings halfway down the first page.

That gun metal grey one looks pretty tough with a rare light colored interior.

cheers,

jj

 

Haha, I'm afraid I'm a silver coupe w/charcol gray interior w/normally aspirated powerplant kind of guy lol. But I do like the asthetics of the "R" version.