Ls400 Handling

[wacko]

My 1998 LS has devloped a wander at motorway speeds, any uneven surface tends to rock the car left and right and cause the car to wander neading constant steering adustments.

My local Lexus garage checked the suspension and advised the replacement of the N/S upper wishbone (the balljoint was worn) and both N/S and O/S reaction struts which has been done, everything else was OK.

The car has done 60,000 miles, has four brand new D8z tyres and a full alignment check and adustment was done when the balljoint was fitted.

Only thing I can think of next is springs and shocks.

Any help or advice please.

[RX-Men-8]

Hi

Just make sure it is not the tyres, especially since you put them on recently. On the IS bad tyre choice can be result in not being able to drive straight on uneven roads and severe tramlining. Especially tyres with a stiff sidewall and square shoulder (sporty low-profile)

RX-Men-8

[wacko]

Hi

Just make sure it is not the tyres, especially since you put them on recently.  On the IS bad tyre choice can be result in not being able to drive straight on uneven roads and severe tramlining.  Especially tyres with a stiff sidewall and square shoulder (sporty low-profile)

RX-Men-8

←

I did have SP300 sports on before which had a big problem with tramlining. The D8z tyres were original equipment on the LS and did reduce the tramlining and general figety ride but the slow wandering is still there. It seems to be more of a reaction to a bump or dip in the road. I only hope its not anything to do with the steering gear although it was checked by the dealer as well and seems OK.

[Pyrex]

Changing tyres from original spec is a risky business.

From what you have written it would seem that the dealer has not cured the problem at all.

This is hardly surprising, as the wear you state in the ball joint is extremely unlikely at the low mileage stated. I did over 200,00 mls with not a hint of a ball joint change.

A rack change yes, as I frequently drive on full lock in tight car parks, but the ball joints held up.

As putting on regular tyres seems to have helped the problem, perhaps a full wheel electonic wheel alighnment would set the car up better. I seem to remember the car being skittish when it hit bumps, and the cure being alignment. Even though it was within the parameters, when reset with even toe in all round it behaved better.

Also not recommended, but I have found...I am a high mileage driver....that reducing the tyre pressure by 3 - 6 lbs from the recommended pressure gives a quieter ride, and the tyres tend to wear more evenly across the crown.

When they are pumped up to the correct pressure they always wore out in the centre which is an indicator of over inflation. At these prices why wear the tyres out quicker than necessary.

Another word of advice, ease up on the roundabouts and the corners, resisting the inertia of the car puts a lot of strain on the tyres, and the edges wear quicker as a result. Not a tracking fault...a driver fault.

Fortunately I have found the LS430 is better behaved, but I still take roundabouts slower than I used to out of respect for the rubber.

:mat: