Just had some brand new front tyres put on Pirelli P0 Nero and I have a slight vibration to the steering the faster I get after about 65 mph.

The strange thing is when I am on some nice smooth tarmac the vibration is gone! This should rule out wheels or tyres since they would be a problem on any surface?

On normal tarmac I get the vibration. It changes depending on the road

Tyre pressures are good. Wheels are straight when inspected. Alignment done very recently. New tyres.

Im of the opinion that since the car feels fine on new tarmac that it could be suspension related since when its tested on normal tarmac it faulters. Being a 30,000 mile 2005 car still on the same shocks and bushes could these components be at fault? Maybe the bushes are worn due to age even if they have not been well used.

Or could it be wheel bearing, however this would be a problem on any tarmac... right?

 

If the problem only appeared with the new tyres, then it's a wheel balance issue or a tyre problem. Check for any side wall bulges etc before driving the car again, if it's a bad tyre it could blow out on you.

 

True actually , if it appeared with the new tyres then its more then likely tyres.

They were new tyres however one tyre had to have a 45g weight put on which I thought was a bit high for a new tyre.

 

sounds like a defective tire.

 

Got the tyre company to repace both front tyres with new tyres and the problem is worst! These tyres are fresh and physically inspected and balanced.

The wobble occures after 60 mph and increases with speed on any tarmac surface.

I have now changed the wheel bearings and the wobble is still there ( with electronic issues as an extra since the change ).

The brake disks are in good condition and pads are fine. The calipers have been serviced 2000 miles ago and no problem with them ever.

The bushes seem fine upon visual inspection.

Tracking is fine. The car drives straight.

The steering rack make a slight whining noise on full lock rarely. Could this be at fault?

I dont want to be constantly replacing parts and I am at a loss what else to do?

 

Have you checked the runout of your brake discs?

 

take the tires to the shop and get re-balanced. this is a classic symptom. or they could also be an out of round tire. (with some major run out) more than likely, tire balance. 65mph is the critical point where this becomes a factor.

 

Just spent a good 10 minutes feeling the rotors.Not sure what the neighbours thought.

They are smooth both inside and out. However I think I can feel a very very slight unevenness from the the centre to the edge. Its very slight but probably enough to cause a problem. I certainly hope it is this.

The rotors have some meat on them. I would hazard a guess 40% left.

I think I will put some new rotors on. Im going to the Nurburgring in a few months time so I expect the brakes will be getting a good bit of use.

 

you cant feel runout with rotors, and if you have some, you will only feel it under braking. under cruise, if they are warped , they push the pads in the calpers so, you cant feel it.

 

I do use heavy braking a lot but always careful to make sure they cool down properly too. They could be warped even with this precaution? I am running EBC yellow pads which are brilliant! Either way I will probably change them since there isnt much else to change.

 

nah.... if you heavy brake, you will feel the warping in the pedal .....very obvious!!
the vibration in the steering has to be balance of the wheels and tires. even though they are balanced.... do it again. just the fronts, check them out. Should be smooth as silk.

 

Yea, you cannot feel runout. Runout is the measurement of the movement from true vertical of the rotor as it turns. A warped rotor is the warping of the rotor surface but might not include any issue with the hub portion of the rotor. If runout is excessive it is possible to feel slight vibrations at higher speeds. I have experienced this myself.

The pads will wear until the material is clear of the excessive runout. However, with excessive runout there will also be pulsing in the brake pedal.

It is true that 99% of the time your symptoms are caused by out-of-balance, and/or out-of-round tires. Before you replace your rotors, you might want to get them professionally checked. No sense in replacing good parts.

Also, if you are getting the new tires from the same supplier, the issue may be with how they are storing them which may be causing them to be out-of-round. It could alo be a manufacturing defect in the tires that affects the "lot" of tires that were made at the same time.

Just thinking out loud.

 

And I was so close to buying new rotors. Yes what your saying does make sense. I dont get pulsating when I brake.

The first set of tyres were from a different supplier but fitted with the same tyre shop. However he did store them for 2 months.

The second set had an out of round tyre and they were replaced.

The 3rd set are round when checked on the wheel balancer and still problem persists.

I may look into going to a totally different tyre shop and getting the tyre balance checked. And if nothing improved replace them at a different tyre shop.

 

No, actually there is radial run out. ("vertical run out") which is rarely ever seen unless the rotors are the wrong ones and are not centered properly, OR, there is axial run out, and this is where the rotors wobble horizontally. this is the MOST common. and, the pads wont wear down and have no effect just by the nature of the pads being able to be pushed back in the calipers when they are not being applied by the brake pedal. the pads will NEVER "clear" the runout because that's not how the braking system works. they are always left after brake application to just float over the surfaces and if there is contact, there is nothing to keep the pads in place but the fluid in the lines and calipers.

If you have a vibration, its the tires balance or its runout.

 

See if the centering ring of the wheel is not broken or improperly applied