Wheel shudder

[martinlaw]

Need some suggestion please - my Sport at around 60mph the steering wheel starts to shudder as if the wheels are out of balance but they have been checked twice and are ok.

I have had the front discs skimmed and checked the front hubs, they seem ok.

There does not appear to be any play in the suspension bushes.

What else could be causing this?

Thanks,
Martin.

[GTWayne]

Martin, it may be worth deflating the front tyres ( off of the vehicle obviously ) and rotating them 180 degrees around the rim and then re-inflate/balance and see if this makes a difference. Also was it the same balancing machine that checked them the first two times? It is not inconceivable that the machine may be in need of calibration.

[Storer]

Has the car been standing for a long time (month +)? This can cause vibration as can a small defect in the tyre.

Have you got another Ultima owner local to you that would swap wheels for a short run to see if the problem is tyre/wheel or something else on the car?

[martinlaw]

GTWayne said:

Martin, it may be worth deflating the front tyres ( off of the vehicle obviously ) and rotating them 180 degrees around the rim and then re-inflate/balance and see if this makes a difference. Also was it the same balancing machine that checked them the first two times? It is not inconceivable that the machine may be in need of calibration.

Hi Wayne,

Will try rotating the tyres. They were balanced on different machines.

[martinlaw]

Storer said:

Has the car been standing for a long time (month +)? This can cause vibration as can a small defect in the tyre.

Have you got another Ultima owner local to you that would swap wheels for a short run to see if the problem is tyre/wheel or something else on the car?

Thanks for the advise Paul - the Sport is moved at least once a week and the tyres were inspected very closely when they were last balanced. Will try and source some other wheels to try.

[Crazy of Cookham]

Hi Martin

Had exact same symptons on my Canam last summer, got real bad on way back from LeMans. Changed suspension mounts and re balanced wheels solved problem. I suspect it was the suspension although not so bad sleeves were loose when removed.

[martinlaw]

highflyer said:

Martin may be able to help out if you want to take a trip over and try the wheels off mine, regards Russell.

Hi Russ,

Thanks for the offer, it is appreciated. The front wheels have 4 studs, is your Canam the same?

Also Kyle tells me you are having some larger splitters and front wing vanes made - I would be very interested in some myself - how much are they?

Cheers,
Martin.

[Steve_D]

I would replace the bushes first.
Only cost a few quid and a couple of hours to do.

Steve

[Davrianman]

Hi Mart,

My Uncle had a similar problem on his Volvo many years ago. After spending thousands on new driveshafts, hubs, disks etc, the garage finaly found it was water inside the tyre. It had got in there from a faulty airline... Above 60mph the water spread around the tyre and the vibration went away. Between 50 and 60 it went round in one place causing the vibration. Below that speed it just sat at the bottom of the tyre and was not a problem...

Unlikely that this is the cause, but still worth investigating!!

Cheers,
Mart

[martinlaw]

Davrianman said:

Hi Mart,

My Uncle had a similar problem on his Volvo many years ago. After spending thousands on new driveshafts, hubs, disks etc, the garage finaly found it was water inside the tyre. It had got in there from a faulty airline... Above 60mph the water spread around the tyre and the vibration went away. Between 50 and 60 it went round in one place causing the vibration. Below that speed it just sat at the bottom of the tyre and was not a problem...

Unlikely that this is the cause, but still worth investigating!!

Cheers,
Mart

That's a good point Mart, I am having a new set of tyres on my GTR next week so I will have the front tyres removed from the Sport and checked at the same time.

Cheers,
Martin.

[gdr]

Don't think worn bushes would cause wheel vibration (didn't on my Ultima when bushes gone, but handling was completely shot). I recently had extreme problem with a set of Yokos on Exige that could not be balanced and vibrated badly from 60 mph up - on closer inspection it looks like a front tyre with the wheel sized hole not exactly in the centre. The thing was balanced, but out of round. Not uncommon apparently.