I just bought a 2002 SC430 last week. Yesterday I took it out to drive to work for 50 miles.

My observation is at highway speeds, the car wonders a bit so that I have to use two hands to hold the steering wheel to keep it straight with minor correction.

I know the steering wheel is kinda loose and light which doesn't help at all. Besides the coilovers (which we have to wait for another month), will a front strut bar tighten up the front end? I have a front strut bar on my 2001 Nissan Maxima and it really tightened up the front quite a bit.

 

Maybe an alignment issue?

 

Not sure about alignment. The car doesn't pull to either side.

My Nissan had the same issue of wandering/loose front end before I put in the front strut bar. That's why I am thinking along this way.

 

Welcome to the list. Did you run a CarFax/AutoCheck on the car--could be the aftermath of a hit . . .

 

Both Carfax and AutoCheck are clean. It is a 2-owner car and in good condition. No sign of previous damage.

 

i just alligned mine at firestone 179.99 for lifetime allignment and its much better and at high speeds 50+ MPH and low speeds im driving straight as an arrow. It might be worth checking that also make sure your tires are balanced correctly and that none of the rims are bent.

 

Hmmm.. Im wondering has Lexus updated the steering and suspension on 2006+ facelift?

My SC (2010)'s steering is quite stiff and communicative, and the suspension is not too bad either.. the car handles well and feels planted up to the limiter (not that i have been there ) - BTW, limiter on ME spec is 175MPH

 

I am sure from 2002 to 2010 there has been a lot of improvement.

 

There was a change to the front suspension system in the 06+ update. Most folks notice a much smoother ride with an 06+ compared to a 02-04.

However, in reading jzwu (how does one pronounce that, by the way), my first thought is this...

Are you running Run-Flat tires?

The runflats are notorious for making the car a both a) fidgety on the highway and b) makes the car tend to follow the seams in the road (which don't always correspond to the lanes)

 

Funny thing is the previous owner changed two new front tires to standard tires (245-40-18) and the two rear tires are still Dunlop run-flats.

Do the run-flats make a difference on the rear too? I am going to do a road force balance.

 

Bad setup. Yes the runflats will make a difference on the back also. Plus, never mix tires. Bad handling!

 

Guess I found out the problem. Thanks!

Now I need to change the two rear tires which still have very good tread left.

 

You could make a couple runflat tire swings

 

Jack up the car and see if you can wiggle the wheels, or have someone else check the ball joints for you. It could be a few things.

 

I like the swing idea! Probably get a bad ride on that too! lol