sirrob11

I took my 2005 LS430 to the dealership today because of a steering problem. On longer trips traveling 55mph and higher I noticed the steering wandering back and forth/ left and right. It overcompensates constantly. After a while of driving it becomes quite tiresome to steer a little left after going too far right then steer a little right after going too far left and over and over. The car steers left or right but never exactly straight for even a split second!

They are lookng over the obvious stuff such as tire pressures and alignment. Any thoughts?

sirrob11

No, the dealer did not have any thoughts either.

GRAND_LS 4

iTrader: (2)

This is usually a problem with MUCH older cars, with higher milage. In your case, it might be your Rack. Because I cant think of any other part that can be worn out on a '05.

sirrob11

I first noticed it on a long interstate trip only days after new purchase with about 200 miles on the odometer!

encore888

Perhaps to do with tire alignment/pressure?

DDLexus

I found that some tires, particularly the larger (i.e. wider) tires tend to wander a bit on some roads. I think they are inclined to find the lowest point or most compacted part of the road. You know, the most worn area where rainwater always puddles. My 5 series bimmer tracked like it was steering itself. annoying, but that's what happened.

So, maybe the road in conjunction with a fat tire leads to wandering..

encore888

Our LS had a slight wander at first, but after several weeks it has gone away and everything seems fine. After the service (tire pressure upped, oil changed), the car seemed to handle even better!

sirrob11

Thanks all. Dealer checked the car, including the alignment and said everything was in spec.

I noted the tire air pressure was 38-40psi and lowered them to 33psi all around. I can only be certain if things changed on an interstate going 55+ after a few minutes. Have yet to notice any improvement.

vicpai

.....I'm very sensitive to this sort of thing too!!! Alignment is a very tricky thing to get exactly right. Depends on the kind of equipment they have etc. (computerized laser alignment machine).....Ask them to make sure they're checking everything: Not just the toe, but caster as well. Usually there is a "range" specified. Ask them to give you a "little more caster" (within the specified range, of course) for better straight-line stability. My LS (although not an 430) exhibited similar behavior, and after 2 visits to Longo Lexus, and speaking with the lead Tech they got it right

sirrob11

Thanks, I will give your suggestion a shot.

houstonnw

I had the same problem and the dealer also "checked" the alignment and found it "within spec".

I took my car to a highly recommended independent shop and he found that the alignment could be improved. Specifically he made sure there was a slight amount of toe-in and a slight amount of negative camber (tops of the wheels closer than the bottoms).

Unfortunately the caster is not adjustable. This is similar to the rake on a chopper and would help the car to go straight and improve the off center feel IMO.

The toe and camber changes made a huge difference. The car is still no BMW but it does not wander nearly as much as it did. I would suggest finding a good alignment shop, maybe one with experience setting up race cars.

Also the stock Dunlop SP5000's have a reputation of having soft sidewalls. I originally increased the air pressure but after the alignment I was able to reduce it back to the recommended 32psi.