Mk4 gs 300h suspension issue

[essldn]

I seem to have issue with my17 plate gs300h. Everytime I turn both way close to full lock. The wheel bounces like I've gone over a rick. Knocking sound too. 

I suspect its control arm issue as I has similar issue on a merc

Am I still under warranty and is this kind of issue covered ?

[rayaans]

7 minutes ago, essldn said:

I seem to have issue with my17 plate gs300h. Everytime I turn both way close to full lock. The wheel bounces like I've gone over a rick. Knocking sound too. 

I suspect its control arm issue as I has similar issue on a merc

Am I still under warranty and is this kind of issue covered ?

Sounds normal to me. Likely to do with cold weather and summer tyres.

[essldn]

1 minute ago, rayaans said:

Sounds normal to me. Likely to do with cold weather and summer tyres.

That's normal?!

[cruisermark]

yes - i've had it alot the past week aswell on my LS430

[rayaans]

58 minutes ago, essldn said:

That's normal?!

It's normal in most rear wheel drive cars or those with a long wheelbase 

Usually solved by winter tyres in colder months. It's called crabbing. Basically the tyres skipping along the surface trying to get grip 

[KayCee]

yes mine too more noticable now cold weather here

[Kijan]

I agree that winter is worse - I was concerned even in the summer that on the full lock small uneven surface with small speeds caused weird body roll of the car, but I've said that just before Lexus big service and they went through whole susoension which was excellent and told me that with this size of car and rwd its normal and nothing to worry about. 

Possibly if you could record video of the sound and how car perform this could be more helpful to check? 

[johnatg]

It's all to do with Ackermann steering geometry. Ideally, both front wheels should travel a true radius, but the geometry is a compromise between achieving that and having good handling, roadholding and steering feedback (not that there is much), etc. It simply isn't possible to get all that exactly right. So the wheels don't follow a correct radius, so they 'fight' against each other. At high steering angles and slow speed, this leads to one tyre 'skittering' against the road surface. That's what you feel.

When it's cold the tyres are less able to compensate by distorting because they are stiffer than when they're warm.

Wikipedia has an article describing it all in detail.

https://en.wikipedia.org/wiki/Ackermann_steering_geometry

Especially see the external links.

[essldn]

An update: got new tyres on and no issue at all now. The old tyres didn't look weird or anything so not sure what was causing it. 

[rayaans]

Which tyres did you have and which ones did you change to? 

[essldn]

22 hours ago, rayaans said:

Which tyres did you have and which ones did you change to? 

I had Goodyears on them. I've decided to put budgets on them as I won't be driving more then a few miles a day for a year. 

[Pielight]

Happens with my GSF particularly with cold tyres.

[rayaans]

On 12/21/2021 at 4:04 PM, essldn said:

I had Goodyears on them. I've decided to put budgets on them as I won't be driving more then a few miles a day for a year. 

Interesting.

Likely tyres were Goodyear eagles which are quite high performance summer tyres so tend to become rock solid in winter causing this effect

[Linas.P]

On 12/21/2021 at 4:04 PM, essldn said:

I had Goodyears on them. I've decided to put budgets on them as I won't be driving more then a few miles a day for a year. 

Just be clear - good HP summer tyres does this because they generally have "aggressive" patterns (i.e. deep grooves to prevent aquaplaning) and too much mechanical grip so that they can't just drag across surface and instead when cold and hard they start skipping on the surface. The only reason why budget tyres don't cause crabbing is that they simply don't have enough grip to fight each other at extreme steering angles and basically they are being noticeably inferior.

 So basically you have downgraded the tyres from excellent to tyres which may save your life, to budgets which are unpredictable and could suddenly loose grip unexpectedly at any moment and at any speed, just because of non-issue which only ever happens on few cold days in winter?! 🤯

[KayCee]

Totaly agree with Linas its due to the wide steering angle have you noticed you can usually do a full turn in the road just like you see on yank films i love it.

the bump on full lock is of no concern

[KayCee]

Incidentaly I Have Eagles on my car