Ls430 Heavy Steering

[restor]

On an in-warranty '06 LS430 (sport edition) the steering is very heavy. The steering also pulls slightly right and appears to require more correction than would be expected at highway speeds.

Some questions:

1.

Is there a difference in the P/S pump between sport ("euro-tuned suspension") and non-sport models?

2.

Is there a solenoid screen on the LS430 that might need to be cleaned?

3.

Could this be a problem with the P/S pump or with a flow control valve?

The dealer says that "this is the way the car drives" in response to a request for in-warranty repair, but I have driven other LS430s and the steering is much lighter on those cars. The dealer indicates that the alignment is OK. Will take this car to another Lexus dealer, but want to be able to point that dealership in the right direction.

Thanks.

[Robert Young]

I have a 2006 LS 430, but not the sport package. Can't help much on the steering question, as mine is fairly light unless I'm pushing it pretty hard. When the car working hard it now shows significant understeer, there is a lot of centering force on the wheel and that is a different source of stiffness than that related to the power steering assistance. However, I would expect that your sport suspension would be better than my base suspension in this respect. I just purchase the rear roll bar for the sport package and plan to install it, that may help reduce a bit of the understeer on my car (front roll bar is the same on all LS 430s).

As far as pulling to the right, I've found that the Dunlop 5000S 245/45R18 tires on the factory wheels that came on my car really want to following the road crown with the factory alignment and that is generally a slight pull to the right. See if you get a companion pull to the left while driving on the far left lane of a one way street or anyplace else you can find with the road falling away to the left, that is what I observe in my car and there is little pull if the road is really flat. If this describes your car, you may need to see somebody who really knows alignment to help with changes to the factory specifications.

[VMF]

when the car is stopped, when you turn the wheels do you hear the whining noise?

[1990LS400]

Here is a link to power steering pump and parts for an 06 LS430: http://www.lexus-parts.com/assembly.asp?id...10&year=167

The basic pumps seems to be the same but there are lots of variations in other parts depending on the "Mark" designation - I do not know what the "Mark" means.

I clearly remember a thread on this forum started by a person who drove a number of non-sport LS430s and then bought a sport version without driving it. He was not happy.

[ChasHutch]

Here is a link to power steering pump and parts for an 06 LS430: http://www.lexus-parts.com/assembly.asp?id...10&year=167

The basic pumps seems to be the same but there are lots of variations in other parts depending on the "Mark" designation - I do not know what the "Mark" means.

I clearly remember a thread on this forum started by a person who drove a number of non-sport LS430s and then bought a sport version without driving it. He was not happy.

I have an 05 LS430 "Sport Edition" (purchased used 2 weeks ago). I, too, noticed that the steering "pulls" a bit on different roads. The steering "seems" heavy depending on road surface (crown in the middle, tends to push the steering one way or the other). I have driven numerous cars with "High Performance" tires and this seems to be the case with all. The car I traded for the LS was an 03 Z06 Corvette with slightly larger tires than the 245/45Z18's that are on the LS, and it did the same thing. Keep in mind that the tires on your car are likely wider than what you are used to (they literally take up more space on the road surface).

For the record, I absolutely LOVE the way the car handles. The steering is responsive, not mushy or lacking at all.

Do I miss the 405hp and handling of the vette? Of course, but nothing I have driven (including mom's S-class or 745) comes close to the overall experience (handling, fit & finish, interior, driver amenities, cust. service, etc) IMO.

If Apple made a car, it would be the LS430.

Hutch

[Robert Young]

FYI, found this revised TSB on vehicles pulling to one side. Seems they just added 2007 applicability, probably a lot ot do with all the cars in So. Cal. coming in with the larger option wheel sizes.ST004_01___Repair_Manual_Supplement_Vehicle_Pulling_To_One_Side_.pdf

[restor]

Thanks for all your comments.

when the car is stopped, when you turn the wheels do you hear the whining noise?

No.

As far as pulling to the right, I've found that the Dunlop 5000S 245/45R18 tires on the factory wheels that came on my car really want to following the road crown with the factory alignment and that is generally a slight pull to the right. See if you get a companion pull to the left while driving on the far left lane of a one way street or anyplace else you can find with the road falling away to the left, that is what I observe in my car and there is little pull if the road is really flat. If this describes your car, you may need to see somebody who really knows alignment to help with changes to the factory specifications.

This does describe my car exactly.

FYI, found this revised TSB on vehicles pulling to one side. Seems they just added 2007 applicability, probably a lot ot do with all the cars in So. Cal. coming in with the larger option wheel sizes.ST004_01___Repair_Manual_Supplement_Vehicle_Pulling_To_One_Side_.pdf

Thanks, that does help A LOT.

I found that putting on 17" rims and pumping up the tires to 38psi cold helps. The car pulls, but much much less than with the 18" rims. It turns out that the automobile I'm speaking of does not have the sport edition suspension. I notice that with the 18" rims, when stopping hard the steering wheel turns in accordance with the surface of the road. If the road is flat, when braking hard the steering wheel stays straight, but if the road slopes right the steering wheel turns hard right when stopping hard. Obviously this is a problem. This happened dramatically with the 18" rims, and much less dramatically with 17" rims and overinflated tires.

With the overinflated tires the car drives really well, although I would like to see how it rides with new tires and a new alignment (the 17s have about 22k on them, and are the Dunlop SP Sport 5000s). Apparently Lexus of Palm Beach recommends 40psi all around on 18s ("for ride"). I called them about it several times and they didn't call me back - I got this information from a friend with an '06 UL who indicated that the fellow who comes out to change the battery for snow birds told him about Palm Beach's inflation recommendations.

Thanks a lot for all the help, it's really appreciated! If you have any other comments on this subject I'd love to hear them.