Vibration from what feels like the drive shaft?

[DaftMule]

Hi,

Have a 55 plate S-Type diesel.  Had it a few months and am over the moon with it but recently, I have noticed a bit of a vibration happening between about 60 and 70mph.  70 seems to be the spot where it reaches that resonance peak which gives the worst, constant vibration.  Below that it is almost like the vibration fades in and out and you don't feel it at all below about 45.

It feels like it's coming from the prop shaft but I guess it could possibly be something to do with the wheels and their alignment?  It's not awful by any stretch, just a little annoying and definitely a little worse now than when I got the car.

Was going to send it in to the garage I use for a bit of investigation but thought I'd ask here first as it may be something common?

Thanks.

[Old Peter]

Hi Adam,

Looking at the cheapest option it is worth checking your tyres first.  I had this problem on a Rover and checked the tyres by feeling round the tyre walls and found a bulge on one front tyre, probably from a pothole.

Regards,

Peter.

[dattrike]

38 minutes ago, Old Peter said:

Hi Adam,

Looking at the cheapest option it is worth checking your tyres first.  I had this problem on a Rover and checked the tyres by feeling round the tyre walls and found a bulge on one front tyre, probably from a pothole.

Regards,

Peter.

I agree, I had the same on my Rover 75, sounded like a wheel bearing gone on the rear, checked the tyres, looked OK

but one was worn down and looked like a thrupenny bit (old money). New tyres cured it.

[DaftMule]

Got the wheels balanced.  One was apparently a bit "buckled".  It seems to have 90% sorted out the vibration anyway.  They swapped the wheel they balanced onto the back and did the tracking too as it was out a bit and now the car feels quite different to drive, but not in a good way!  I took it back to them after 2 days to get them to check it again as the car was definitely wandering off to the left.  They tweaked it slightly and it is better but the car still feels different.  Before this work, it felt like you could happily let go of the steering wheel and the car would remain rock steady (other than the vibration issue).  Now it just feels like it picks up any blemish in the road surface and wanders around.  

Amazing how much difference rotating the wheels can make!  In fairness though, the only bad thing on the car is the wheels.  The previous owner obviously had an affinity for kerbs and one in particular is flaking quite badly.  

[Mr Lawrence]

Have you checked your tyre pressures? Critical to any car!!

Get the garage to swap the wheels from the front to back, if it's a balance problem then it should transfer.

front wheel imbalance is felt through the steering wheel 

rear wheel imbalance is felt through your seat. 

Also, due to the camber of British roads every car will drift left always, if it's pulling more violently then you have a definite steering problem. 

[DaftMule]

Yup, tyre pressure was checked during the balance and tracking and I keep an eye on them regularly anyway.

Don't get me wrong, it's not violently pulling left...it's just a bit of gentle drift and it's quite difficult to tell most of the time because the roads are in such a shocking state around us!  Just feels different to the way it felt before the work.  

It's probably just me being pedantic! :-)