Car not stable at speed.

[essldn]

2 hours ago, Vlady said:

I have asked Lexus Glasgow to check the suspension a few times and they never found a fault, in a last three years I have done 4 or 5 times wheel alignment and the car still not as direct as I got used to based on my previous cars. Lexus does well when you go well above speed limit though! 🙂

I have done just under 60k and I noticed this behaviour when the car was at 30k! So I can't say the suspension is/was tired. I got used to this by now, I think! 🙂

Road forcing balance - I never heard of it, does dealers do that or it needs to be a specific garage?

Thanks for the input Shane.

Vlad

I had my car serviced twice and they never mentioned any suspension faults. I had to specify with a different garage to do a proper suspension check which was when they found my worn control arms. 

Good tyres are also key

Road force balancing- will need to research and find local garages. Quite rare tbh

[Vlady]

2 hours ago, essldn said:

I had my car serviced twice and they never mentioned any suspension faults. I had to specify with a different garage to do a proper suspension check which was when they found my worn control arms. 

Good tyres are also key

Road force balancing- will need to research and find local garages. Quite rare tbh

I will ask Lexus to check front suspension again during MOT check.

Thanks 

[essldn]

27 minutes ago, Vlady said:

I will ask Lexus to check front suspension again during MOT check.

Thanks 

Use this website http://www.balancemycar.co.uk/ to find you nearest road force balancer 

[Vlady]

Many thanks @essldn

The closest one is in Carlisle! 

[GS.450.H]

Well. I have the exact same 'problem' that @Vlady has with my Lexus GS450 2013 (with AVS)

I don't really know how to explain but when there's any slight wind, the car is all over the place and i have to really concentrate to keep the car inbetween te lines. It's not my aligntment, rims, or tires.  I have 4 new Hankook tires, 4 rims that are perfectly straight and the car has been aligned several times (last time with a Road Force Hunter).

I let my mechanic look under the car to see if there were any obvious signs of wear on my suspension but he said the car looked super clean and he did'nt see anything strange. 

This is not the first post which i can relate to, i saw some on the american forums aswell but i really need to know if someone has fixed this problem, otherwise i'll sell the car, for only this reason. i love it but i can't keep driving like this....

Please, if you read this and you know a solution let me know, i'd really appreciate it!

[Mike_Mac]

2 hours ago, GS.450.H said:

Well. I have the exact same 'problem' that @Vlady has with my Lexus GS450 2013 (with AVS)

I don't really know how to explain but when there's any slight wind, the car is all over the place and i have to really concentrate to keep the car inbetween te lines. It's not my aligntment, rims, or tires.  I have 4 new hankook tires, 4 rims that are perfectly straight and the car has been aligned several times (last time with a Road Force Hunter).

I let my mechanic look under the car to see if there were any obvious signs of wear on my suspension but he said the car looked super clean and he did'nt see anything strange. 

This is not the first post which i can relate to, i saw some on the american forums aswell but i really need to know if someone has fixed this problem, otherwise i'll sell the car, for only this reason. i love it but i can't keep driving like this....

Please, if you read this and you know a solution let me know, i'd really appreciate it!

I’ve been doing a lot of digging on this recently and regardless of what your mechanic has said I would think about replacing your control arm bushes and the small link with two ball joints on it at the bottom of the front suspension. Mine looked ok too… but they were not!

Ive replaced those, and a lot more besides, including some in the rear, and it’s made a significant improvement - a stiffer set of sway bars also made a huge difference too. Ultimately these cars are older now and rubber doesn’t last forever.

Another thing to check is the subframe braces at the rear. Both them, and the small arm that connects them to the subframe can fail due to corrosion and will make the rear end unstable (albeit your mechanic should have spotted this so it’s unlikely in your case).

Hope that helps!!

[Vlady]

4 hours ago, GS.450.H said:

Well. I have the exact same 'problem' that @Vlady has with my Lexus GS450 2013 (with AVS)

I don't really know how to explain but when there's any slight wind, the car is all over the place and i have to really concentrate to keep the car inbetween te lines. It's not my aligntment, rims, or tires.  I have 4 new hankook tires, 4 rims that are perfectly straight and the car has been aligned several times (last time with a Road Force Hunter).

I let my mechanic look under the car to see if there were any obvious signs of wear on my suspension but he said the car looked super clean and he did'nt see anything strange. 

This is not the first post which i can relate to, i saw some on the american forums aswell but i really need to know if someone has fixed this problem, otherwise i'll sell the car, for only this reason. i love it but i can't keep driving like this....

Please, if you read this and you know a solution let me know, i'd really appreciate it!

Hi, the problem I had was never fixed and never new what caused it, all I could do to make sure the car drove more stable is put suspension on Sport Mode. This was one of my main issues with the car, even skoda Octavia I had as a courtesy car was holding the road better.

I also had 4 new tyres (Good Year) fitted, wheel alignment was done couple times at Lexus Glasgow and it still was not stable - any move with your head and you already half the way to another lane!

I am sorry to hear there is another owner that suffers from the same problem! I wish I could get a shot in another GS to compare, that way I would spend money on suspension etc but mine was checked and all seemed fine, plus when I bought the car the mileage was only 33k miles so shouldn't be worn!

I hope you will find a cheap solution to it and soon. Otherwise the car was really good!

Good luck!

[GS300h2014]

It may reassure you know that the Mk4 GS is not inherently unstable. My 2014 GS300h with AVS feels totally planted on the road at speed. It feels very safe & stable at high speed, more so than any other car I've driven. It's behaved like that since new and has now done 67k. Presumably you've had the front hub bearings checked for play?

[hazelnut]

On 1/11/2023 at 7:03 PM, Mike_Mac said:

I’ve been doing a lot of digging on this recently and regardless of what your mechanic has said I would think about replacing your control arm bushes and the small link with two ball joints on it at the bottom of the front suspension. Mine looked ok too… but they were not!

Ive replaced those, and a lot more besides, including some in the rear, and it’s made a significant improvement - a stiffer set of sway bars also made a huge difference too. Ultimately these cars are older now and rubber doesn’t last forever.

Another thing to check is the subframe braces at the rear. Both them, and the small arm that connects them to the subframe can fail due to corrosion and will make the rear end unstable (albeit your mechanic should have spotted this so it’s unlikely in your case).

Hope that helps!!

I have attached a parts diagram of the front suspension on the GS450h. Do you mean the anti-roll bar link ?  I would not think this does anything in a straight line, but I am not a suspension engineer. My 2009 is a bit wandery/tramliney in a straight line, but I assume that is due to having massive wide tyres?

[Mike_Mac]

4 hours ago, hazelnut said:

I have attached a parts diagram of the front suspension on the GS450h. Do you mean the anti-roll bar link ?  I would not think this does anything in a straight line, but I am not a suspension engineer. My 2009 is a bit wandery/tramliney in a straight line, but I assume that is due to having massive wide tyres?

No, it’s not the ARB link - it’s the control arm bushes I’m talking about, which are in diagram 48-02, not that one you added there.
 

See parts 48075 and 48076 on the picture I’ve attached for what I mean. The other arm I mentioned is 43330 and 43340

[hazelnut]

20 hours ago, Mike_Mac said:

No, it’s not the ARB link - it’s the control arm bushes I’m talking about, which are in diagram 48-02, not that one you added there.
 

See parts 48075 and 48076 on the picture I’ve attached for what I mean. The other arm I mentioned is 43330 and 43340

Ahh, that makes more sense. My 2009 GS450h (86k miles) I just got it running, but it is a bit unpredictable in the steering department, dangerous even. I can't see how it passed its MOT last week like this.  I guess it would be something they don't test at the MOT ?

[Mike_Mac]

34 minutes ago, hazelnut said:

Ahh, that makes more sense. My 2009 GS450h (86k miles) I just got it running, but it is a bit unpredictable in the steering department, dangerous even. I can't see how it passed its MOT last week like this.  I guess it would be something they don't test at the MOT ?

Correct. If bushes etc aren’t visibly worn or have play in them it’s fine. Mine was like that initially, but sway bars, new shocks and swapping of key bushes did the trick (sway bars not essential, but they make a night and day improvement!).

[hazelnut]

1 hour ago, Mike_Mac said:

Correct. If bushes etc aren’t visibly worn or have play in them it’s fine. Mine was like that initially, but sway bars, new shocks and swapping of key bushes did the trick (sway bars not essential, but they make a night and day improvement!).

I will check the alignment with my Dunlop optical gauges at the weekend, I assume it should be running 0.5 degree toe-in?  The lower ball joints are available for around £30 each, if I get time I will take one off and check it for play.

[Mike_Mac]

19 hours ago, hazelnut said:

I will check the alignment with my Dunlop optical gauges at the weekend, I assume it should be running 0.5 degree toe-in?  The lower ball joints are available for around £30 each, if I get time I will take one off and check it for play.

If you're looking at eBay for those lower balljoint arms I'd be careful. I fitted one a while back and it din't last long at all - went back to Lexus OE and the quality was significantly better.

Ref alignment specs - not sure exactly, but sounds about right. As saidm, though, alignment can be bang on when static, but if bushes are allowing movement under dynamic load then that'll go south rapidly.

[hazelnut]

1 hour ago, Mike_Mac said:

If you're looking at eBay for those lower balljoint arms I'd be careful. I fitted one a while back and it din't last long at all - went back to Lexus OE and the quality was significantly better.

Ref alignment specs - not sure exactly, but sounds about right. As saidm, though, alignment can be bang on when static, but if bushes are allowing movement under dynamic load then that'll go south rapidly.

So I have reverted to driving my 1998 Alfa Romeo (cost £350) which drives significantly better than the Lexus. I usually try to go for decent pattern parts such as Febi Bilstein, I have not yet discovered a source for Lexus parts. The local dealer doesn't seem to want to know, not that you can park there as they have evidently not been able to sell many cars for a while so they have so much stock you have to park on a few streets away.