Strange juddering sensation

[Ace8800]

 @ continuation sheet

[J Henderson]

[emoji23] @ continuation sheet

This phenomenon seems to be tyre dependant. My car does it with michelin PSS fitted, but not with the winter tyres it has now, or with my previous set of summer tyres (Hankooks).

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[JeffL]

Couldn't believe this topic appeared as I had been thinking of mentioning it myself. I have experienced this previously on my current GS300 (2007) and many years ago when I had several Volvo 940/960s which had fantastic turning circles. My current GS300 has Goodyear Efficiency Grip Performance 225/50 R17 W (98), 4 new tyres fitted at mileage 59,385. Current mileage is just over 65,000 and I've noticed this problem over the last few weeks so would agree that cold weather might have something to do with it. It is a similar noise to that heard on the Mercedes video above kindly upload by NemesisUK and I would described it as feeling like the tyres are sticking and the jumping. So it appears to be what he/she is experiencing i.e. the comment below. I get it mainly when reversing off my drive at full lock but the other day got it moving forward on full lock in a car park when the weather was extremely cold.

On 14/12/2017 at 1:50 PM, NemesisUK said:

Most of the movement is in the tyre itself. Flexing then snapping back, which what one tends to hear and feel.

 

[Guest]

So that's Lexus, Merc and now Volvo do it. John is gonna be busy redesigning all these systems. 

 

[NemesisUK]

You can add Porsche to the list also...

[AmbroseJohn]

17 minutes ago, Comedian said:

So that's Lexus, Merc and now Volvo do it. John is gonna be busy redesigning all these systems. 

 

Compression, combustion & ignition are my thing, wouldn't know where to start with suspension geometry.

[Ala Larj]

This morning was the coldest we've had down here this year and it juddered when I drove forward after reversing off the drive. That's a first so it definitely seems to be temperature related. When I get home this evening I'm going to reverse off the drive straight after I've parked on it to see if it happens then. The tyres should be warm by then. It does seem odd though that manufactures think it's acceptable. It really does feel as if some damage is going on down there when it happens. Surely the vibrations can't be good for the suspension components?

[NemesisUK]

The unavoidable physics of wide low profile tyres.

Unless you want the turning circle of an oil tanker!

[Ala Larj]

2 minutes ago, NemesisUK said:

The unavoidable physics of wide low profile tyres.

 

Yes, I can understand the wider the tyre the greater the problem. Gee, am I glad I don't have a Lamborghini!

[Big Rat]

20 minutes ago, Ala Larj said:

Yes, I can understand the wider the tyre the greater the problem. Gee, am I glad I don't have a Lamborghini!

No your not, not really 😜

[Ala Larj]

I'd only use it in the summer though!

[Jamesf1]

My IS250 used to do it at my old house which required full lock to reverse off the drive, as I went across the pavement and onto the road itself. It was worse the quicker I did it. Rolling backward very slowly eliminated it.Being RWD there is a lot of angle available on the front wheels and you literally drag one of them across the surface if you go too quickly. When doing the turn which causes it, do it as slow as possible, especially at or near full lock.

The juddering is entirley normal and worse in cold temps. I've experienced it in Mercedes, Audi and Subaru and my daughters Yaris does it as well. Winter tyres help as they are a softer compund.

[rayaans]

Yep as mentioned completely and utterly normal.

I've got it on my 4RX. It skips when reversing at low speed no matter what the weather. I've been told tyres make a difference but it won't fully go away. 

It's particularly worse on vehicles with a hefty rear tyres or long wheelbases.

The last Porsche 911 I drove did it, as did a few Mercs and BMWs with wide tyres round back. The 911 was particularly bad. I swear it barely turned whilst reversing and actually skipped for a few cms.

It's basically due to the front wanting to go straight rather than turning when reversing. There's also less contact patch on the tyres when turned. 

[steveledzep]

My RX does it when driving forwards off my drive every morning.  I enter a narrow lane and I'm on full lock.  Only appears to do it from cold, if I return home then go out again it doesn't judder.  Manoeuvring on the drive is ok as it's gravel.

[Ace8800]

Got my car booked in on the 12th..lets see what they say.

[Ala Larj]

8 hours ago, Ace8800 said:

Got my car booked in on the 12th..lets see what they say.

Keep us updated. I'd be interested to know what they say. Mine seems to be getting worse lately.

[Ullevi]

On ‎14‎/‎12‎/‎2017 at 1:11 PM, NemesisUK said:

No, what we are realising from this thread is that with the very low profile tyres and colder weather, we are noticing this 'characteristic' (as Mercedes Benz describe it  ) at extreme lock.

There is no 'poor' design with regard to Lexus or MB come to that.

It is a common feature to many cars as described above.

I can't say I've noticed it with my previous GS (2013 250 F-Sport), but it really is noticeable on my MB SLK.

Just changed the GS for a GS 300h with 18" wheels so will report back if I notice it on the new car.

[Ace8800]

Just got the car back after getting a check over and no issues, i say no major issues. The only thing they said was that the wheel alignment is recommended, they usually charge £99, but for me they will charge £60. 

I for one second do not believe its the alignment as i have no pulling or uneven wear and nor is the steering off centre, plus they only RECOMMENDED, surely if it was off they would strongly advise.

Anyway whilst the mechanic sat with me to take it for a test.. it would not make a noise like it does in the mornings.. but it did very so lightly. His reaction was, its just the way they are.. the went on to say the IS is alot worse, but its nothing to worry about and its just the cars characteristics. 

And thats it.

[is200 Newbie]

Do you keep having to top up the air in the tyres?

 

[Ala Larj]

17 hours ago, Ace8800 said:

Just got the car back after getting a check over and no issues, i say no major issues. The only thing they said was that the wheel alignment is recommended, they usually charge £99, but for me they will charge £60. 

I for one second do not believe its the alignment as i have no pulling or uneven wear and nor is the steering off centre, plus they only RECOMMENDED, surely if it was off they would strongly advise.

Anyway whilst the mechanic sat with me to take it for a test.. it would not make a noise like it does in the mornings.. but it did very so lightly. His reaction was, its just the way they are.. the went on to say the IS is alot worse, but its nothing to worry about and its just the cars characteristics. 

And thats it.

Thanks for the update. I guess I just have to put up with it then!

[Britprius]

As already mentioned the wider the tyres the more noticeable is the effect.

The reason for this is because with a wide tyre the inside and outside edges of the tyre when cornering should follow different radius circles, and be running at different speeds. A physical impossibility. At low speeds the tyre grip is such that the tyre tread must when cornering slip on one edge backwards, and on the other edge forwards on the road surface to maintain the same centre tread rotational speed.

A very narrow tyre only follows one radius, and consequently only needs to run at one speed.

John.

[Ala Larj]

That entirely makes sense John. It also makes sense that it's worse in cold weather when the tyres are stiffer with less natural give in them. My main concern is whether that vibrating/juddering is putting excessive stresses on the suspension or steering geometry?

[Britprius]

6 hours ago, Ala Larj said:

That entirely makes sense John. It also makes sense that it's worse in cold weather when the tyres are stiffer with less natural give in them. My main concern is whether that vibrating/juddering is putting excessive stresses on the suspension or steering geometry?

I would say not although not ideal as the steering, and suspension has to be able to withstand the forces generated when braking hard while cornering, and perhaps hitting a pothole at the same time.

John.

[steveledzep]

Yes, well explained about the different radii John.

 

I had new tyres fitted yesterday as the old ones were at about 2mm.  This morning driving full lock from my driveway on to the lane I had no juddering.  I put it down to the full tread being sufficiently pliant to absorb the differential in speed.  It will be interesting to see at which point it returns as the tyres wear down.  Previous front tyres were Dunlops, got Pirellis now, wonder if this makes a difference too ?

[Ala Larj]

I've got a fair bit of tread on mine. They're Dunlops. Could be a harder compound.