This may be part of the reason, but this does not explain why there is a significant wandering problem on some cars and not others, or most importantly, how to fix your LS if your car wanders.

 

Reduced Cd is not a valid reason. Actually, the opposite is true, the lower the Cd, the more stability and less effect of aerodynamics. Don't be misled by this.

 

As far as changing the LCA bushings, what do you guys mean by burning them out to remove them, like with a blow torch or something? I really want to replace mine to see if it fixes my wandering issue on my 04 with 105k miles, besides I think its due anyways.

 

if you dont have a press dont do it yourself. Its not a hard job if you know what you doing but its a messy one. I used a torch and air hammer to burn the bushings out of the piece of aluminum they are pressed into. Then air hammer the bushing out. You can press them out its alot less messy, since the bushings are liquid filled.they look something like this.

 

The story continues .... Some of you will recall that my LS wouldn't drive straight without wandering all over the road. I replaced my 18" wheels, got 3 sets of new tires, had 4 wheel alignments and replaced the steering bushings and while the car drove a bit better, it still was not satisfactory. The car reached 90,000 miles and the wandering remained. I drove the car but my enjoyment was diminished.

Took it an hour outside the city to a guy who sets up Time Attack race cars to see if he could find the problem and he checked every single item you guys identified. He went over the entire suspension and reported everything was fine. He did a 4 wheel alignment and said the rear was just barely in spec .... and he was able to adjust it. (The rear camber was, as all of you said, was not that bad ) He concluded that if the alignment didn't fix it completely he would look at the variable speed assisted power steering unit ( I think he said it runs on a vacuum ) if I was able to locate the "variable speed power steering diagnostics"

The car drove well on the way home and I will be absolutely amazed if it does not need to go back to him in the spring to fix the variable speed assisted power steering unit. Time will tell. But .... if all it needed all this time was a competent alignment .... and all 3 prior alignments were bad, I may have to break a few faces, lol

Can anyone tell me where I can find the "variable speed power steering diagnostics". I would like to print it out so I can bring it to him IF needed

This story may actually have a happy ending

 

Stu, I think you are barking up the right tree... I have all the mechanicals replaced in mine and I still notice some unnecessary wandering on highway. I have the E-bay bootleg factory manual and there are mechanical diagnostics in section 51 for trouble shooting of this system, and assume there is electrical trouble shooting for the PS ECU as well possibly but I did not dig that deep... if you don't have a copy you can buy for $20 on e-bay or I can try to send you one possibly. Interesting steps I saw were pinching the vacuum line and observing idle speed... also unplugging the electrical connection to the PPS with expected increase in effort at the wheel... you may try that yourself and drive around for awhile and see if disconnecting that electrical power assist has any positive effect.

Good luck slaying this dragon!

 

Tire design/balancing and alignment is usually always the cause for any car to wander. I am very fortunate to know someone that knows how to do a great job aligning cars and also balancing tires...

 

Yup all you needed was a good alignment. You would be amaze how much incompetent alignment mechanics are out there..............that includes the dealer, alignment shop.............what they are and what they claim they can do really doesn't mean they actually can do a good job.

I am lucky to have a local alignment shop that actually knows what they are doing, 105k miles on my LS430, zero suspension component have been replace other then the shocks, it goes straight as an arrow for the last 5 years that I own it.

 

Sometimes its the road you're driving on as some places have deep verticle grooves on the highway, i noticed my 01 LS drifts a little on Las Vegas 15 hwy and the 215hwy but not on the home highways here in Socal. So in my case it was just the highway i drove on.

 

When your car wanders like mine did, it wandered everywhere, all the time, on every road. Driving at 75 mph required a LOT of attention.

I agree that roads are never perfectly flat and may have ruts from heavy trucks and general aging of the road surface. In snow and very wet climates the build the roads "peaked" so the rain and snow drains off the surface, causing a will aligned vehicle to pull to the right.

 

I have an old pickup with a set of wide summer performance tires at 17" diameter and a thinner set of 15" diameter winter tires. With the winter tires the car tracks much more straight and the steering is much quicker to come to center. I suspect that the width of the tire has a lot do with it. We have very humped / rutted roads in Quebec and a wider tire tends to catch different parts of the ruts more. I.e it seems to make the steering more sensitive to imperfections in the road than the thinner winter tire, which rides more or less down the center.

If the problem is fixed by an alignment - great. But if you could track down a set of thinner tires and wheels to do an experiment on it may be interesting. 245 is pretty wide.

Anyhow. This is just an observation. I am not an expert in this area.

 

I was told this by several other people, and you're correct !

I sold my OEM 18" wheels and 245/45 tires. The car now has two set of 17s. The winter tires have always wandered less than the summers .... and the tires are the same size. Its a mystery !

 

Sorry to drag up an old thread, but is there any chance you could get the specs for your new alignment?

 

sorry. I didn't take a print out after he finished.

 

When I lowered my LS400 only 2 inches on Tanabe coils and new KYB shocks the car handled much better but she would also track more often too. I put 18 x 8.5 inch rims that also ran 245/45 R18. The wide wheels will cause the car to track more even if your alignment is perfect. The soft and wide tires really grip the road very well and they will pull the car around a little.