Strange Vibration Problem in One Wheel

[metricspaces]

I've a strange vibration problem that only happens in one wheel. Wondering if anyone has come across anything similar or has any ideas of what may be causing it?

The problem happens when travelling in 6th at 65mph and I let my foot off the accelerator. The front passenger wheel shudders until I get to 55mph. Once I reach 55mph the shuddering stops.

If I put my foot all the way down on the clutch pedal when the wheel is shuddering, the shuddering stops also.

The following have been checked:

1) Wheels are balanced and aligned correctly.
2) Wheel is not buckled.
3) All bushings are fine.
4) Majority of suspension components have been replaced (drop links, complete tie rods, wishbone bushes, springs, dampers).
5) The wheel bearing has been replaced about a year ago.

Any ideas?

 

[s3dave]

Have you tried swapping wheels about and see if it follows?

 

[<tuffty/>]

Could be bush related... check the wishbone rear bush... these are voided type bushes and when they go they tend to make the whole suspension wobbly... you may also find it pulling to the left under braking...

<tuffty/>

 

[Buzzer]

could this be anything to do with the flywheel, especially when it goes when the clutch pedal is pressed?

 

[metricspaces]

Good idea about swapping wheels! Will give this a try.

Wishbone bushes were just recently replaced. Rear ones are the solid TT type and have no cracks. So don't think it's that.

If the problem was flywheel related would it cause vibration in only one wheel?

 

[A3Tom]

Wheel balance weight come off? I know you said they are but have you had them actually checked since the wobble started?

I've just dont the front left balljoint on mine, that cured the banging but also a slight wobble... although it was at all speeds.

It sounds very much like something is out of balance at whatever RPM 65mph in 6th is!.

 

[metricspaces]

Ball joints were replaced too - it's almost a brand new S3 at this stage

This problem existed a few months ago. Balance and tracking were checked. It didn't cure it. The problem has gotten worse now. Worse in the sense that the shuddering is harder. It still happens at the same speeds.

I guess if I swap wheels that would rule out a balancing problem.

 

[A3Tom]

Propshaft?

 

[s3schofield]

put the spare on see if that makes a difference , and prop shaft is a good call they are balanced from the factory with weights could have fallen off

 

[metricspaces]

Prop shaft. That's the same as the drive shaft right?

Looking at the diagram on VAGCAT http://www.vagcat.com/epc/cat/au/A3/1999/201/52/2401704/ it seems to be just two CV joints and a metal bar, this correct? So the only options are to replace CV Joints (or entire drive shaft)?

What do you mean when you say the prop shaft is balanced from the factory. Are individual weights put on it (like a wheel) in order to balance it? How does it become inbalanced? How would you test whether it is balanced and re-balance it?

 

[<tuffty/>]

Never personally known a driveshaft to go out of balance... typical causes are dropped wheel weight, track rod, track rod end, lower ball joint, wishbone front voided type bush, wishbone rear bush... any of these are more likely to be the cause of your issue than the driveshaft tbh...

On rare occasions I have seen aftermarket wheels cause issues where the centres are too large and they don't sit on square... I have also seen some wheel spacers give problems not sitting square from corrosion etc..

<tuffty/>

 

[metricspaces]

Never personally known a driveshaft to go out of balance... typical causes are dropped wheel weight, track rod, track rod end, lower ball joint, wishbone front voided type bush, wishbone rear bush... any of these are more likely to be the cause of your issue than the driveshaft tbh...

Any time I've had an unbalanced wheel before it would shudder when reaching a certain speed and continue to shudder if the speed increased.

This seems quite different in the I don't get any shuddering until I take my foot off the gas at 65mph. It doesn't happen if I take my foot off the gas at 70, 75, 80 etc. But when decelerating from 80mph say, once I hit 65mph the shuddering will happen and stay until I get to 55mph.

All the components you mention here have been replaced within the last year or two. All seem solid. There is a fraction more play from the prop shaf on the problem side, compared to the prop shaft on the other side.

On rare occasions I have seen aftermarket wheels cause issues where the centres are too large and they don't sit on square... I have also seen some wheel spacers give problems not sitting square from corrosion etc..

<tuffty/>

Original 17inch wheels. But I do have spacers. Possibily a cause?

 

[metricspaces]

Swapped the front wheels from left to right and the vibration problem is still there on the passenger side. So obviously not a balancing issue.

* Track rod, track rod end - replaced entire part about a year ago, no play in these.
* Lower ball joint - replaced a few months ago, fine too.
* Wishbone front voided type bush, wishbone rear bush - replaced a few months ago, all look fine.

So what does that leave? Just the prop shaft\CV joints?

 

[s3dave]

can you try it without the spacers?

 

[metricspaces]

Yeah, I was actually thinking of removing the spacers on the front to test that.

Am I right in thinking that the spacer is just a plate that is only held on by the wheel nuts? Interestingly enough, when I took off the problem wheel, the spacer seemed a lot looser than the other side.

I see this guy here had a similar problem with spacers on standard wheels. I'm on standard wheels too. Wheel spacers and vibration

 

[s3dave]

non hubcentric spacers are known to be troublesome

 

[metricspaces]

I've got H&R spaces (10mm front, 20mm rear). I'm pretty sure that they are hubcentric.

The problem described in the link I posted sounds exactly like the problem I am experiencing - vibration in some 10/15mph range. So definitely worth taking them off and seeing what happens.