JohnLX300

iTrader: (2)

I have always had a slight shimmy in my steering wheel. I had warped rotors because when I stepped on the brake, the pulsation got worse. I changed all rotors and pads. The shimming stop. Unitl I reached about 60mph -70mph on the highway is bad. After 70mph it starts to smooth out. And sometimes it doesn't shimmy at all, in all types of weather conditions. Any suggestions?
thanks

lexus114

Well it could be a few things causing it,unbalanced wheel,wheel torqued unevenly,belt in tire shifted,lower control arm bushings.And thats all I can think of @ the moment.It could also be your tripod (CV) joint acting up,although that mostly shimmies when under throttle.

salimshah

The first culprit with a speed related shimmy is the dynamic balancing of the front wheels.

If you want to do some work, you can swap the rear to front ... assuming the rears are balanced right the shimmy should go away.

I would take the RX to a wheel shop and have the tires balanced. This is a generic operation and you can avoid dealer.

Salim

JohnLX300

iTrader: (2)

I have had these tires balanced, and rebalanced. Last time it was only a half gram off. Would this be enough to cause such shimmy?

salimshah

That raises another question .... why does it need to rebalanced again and again. Unless the weights keep falling off there may problems with the tire and or the suspension.

Back to your question about off by a gram (specially on larger rim size) ... it can. Also for some tires their dynamic weight shifts as the tire warms up.

If you have lifetime balance from a tire shop, explain the situation to the tech. Have him/her ride with you to demonstrate if needed.

If you dont, then try moving the tires front to back and see if it makes a difference.


Salim

code58

John- It doesn't make me an expert, but I did spend my life in the automotive field and I am very detail oriented. Have you checked the front end, meaning have you jacked the front up and tried to move the front wheel (from both sides) back and forth to check the tie rod ends, the tie rods (inner ends) and the rack and pinion (steering gear) for wear? If there does not appear to be, I would do what Salim suggested, switch front to rear and vice versa. I did have experience with a set of tires on my wife's '02 Camry. They were rather expensive Yokohama's. They were balanced 3 times in the 20k mi. that I tolerated them and had them replaced. They had vibration even after I knew they had worked hard to balance them perfectly. They had varying vibration at freeway speed, meaning it was not absolutely consistent, would cycle through different phases as you drove at the same speed. I can't stand a vibration but my wife drove the car most of the time. When I finally had them replace them, because I was convinced it was bad tire construction or engineering, they replaced them with Michelin Primacy which have been excellent from day 1.
I did alignment for quite a few years and am reasonably convinced it isn't alignment, unless the car has been wrecked and not repaired properly. Also, whether it relates to your problem or not, go to Centric's site and read what they have to say about pad transfer that causes a feeling of warped rotors and what to do about it. It is valid, and it has actually worked for me, though it may not be what is in play here. Good for future reference. Good luck and let us know how you do.

JohnLX300

iTrader: (2)

Update - I checked the front end hoping to find something. Nothing. Everything in the front-end is perfect. Early this morning on my way to work, about 20 miles away 55mph+, I started out at around 60 -65, no shimmy. A couple of minuted before I get to work the shimmy started guessing that the tires warmed up by then and thed belts shifted within.

code58

John- What kind of tires do you have on it? If you didn't find anything loose (worn), I am guessing that it may very well be a tire problem similar to what I had. Sometimes it would be smooth and later at the same speed you could feel the vibration, although it wasn't smooth very much. The steering wheel did somewhat shimmy (minor, back and forth). If the tires you have are still produced, go to a site like Tire Rack and see what people are saying about them. They sell so many tires,and have a lot of feedback on the site.

JohnLX300

iTrader: (2)

I have Dunlop Rover Tour LT, these tires weren't my choice, when I bought the car I had the dealership put on all 4 new tires so they all would be the same. Since my last update I contacted Dunlop, I am going to Blacks Tire Service, which they claim handle all their warranty claims. They are going to inspect these tires. Is there anyway they can see (visually) even if they take tghey tire off the rim, if there is an issue? Also, tire rack doesn't carry these tires. I could fid them on mavis tire website, in which there reviews state the tire is good.

code58

John- I've only ever had 1 set of Dunlop tires and I definitely wasn't impressed with them. I don't know if they would show anything inside when you dismounted them but I doubt very seriously there would be anything to see since I don't think my tires were coming apart at all, just that the belts or structure was shifting when you drove. I was fortunate in that I bought them from America's Tire (Discount Tire) and when I told the guy I wanted them off, I didn't care what they did with them, fully expecting to have to pay full price for the new ones. I just could no longer tolerate the variable vibration that was impossible to balance out. They gave me zero hassle, and treated me very well on what they charged me to upgrade to the Michelin Primacy. I won't likely buy tires anywhere else because after 2 sets of Mag wheels and several sets of tires, they have treated me like I have never been treated before by a tire company.
I still believe the greatest chances are that your tires are defective in manufacture.

JohnLX300

iTrader: (2)

****UPDATE***** After months and months of harassing the Goodyear/Dunlop Corporation about my Dunlop Rover Touring LT tires, I finally found a tire shop to replace them under warranty. Saturday I bought my Lexus to Blacks Tire Service in Myrtle Beach. The guy behind the counter.....bought a 1999 Lexus RX300 FWD for his wife that he got rid of @ 139,000 because of tranny failure. This place did everything, inspected everything, rebalanced all the tires again, I drove it home and back, told the guy it still rides like *****, so being a fellow RX owner, he said lets get those tires off of there. I have 70% of the tire left. So he recommended (since I have to stay within the Goodyear/Dunlop tire) the Goodyear Assurance Comfortred. Any other Goodyear tires suggestions?

sktn77a

iTrader: (2)

The Assurance ComfortTread should get rif of your problem. They are a very highly rated tire. They aren't an off-road tire but I doubt you do any off-roading.

code58

John- I am glad you are finally getting something done about the tires. I am betting it takes care of the problem. When we had the problem with the Yokohama's on my wife's Camry, it always bugged the daylights out of me when I drove it (not real often) because I can't stand a vibration of ANY kind. I was convinced that it was the tires, not balance because I put it up on stands (all around) and had my wife slowly run it up to about 75 MPH. You could see the cyclical imbalance (smooth and then vibrate but not any consistent pattern to it). With 20k mi on them, the tires looked like new (720 tread wear rating), but I decided if I had to throw them away, I couldn't tolerate another mile of that. The Michelin Primacy's have been like silk from minute one and also wear fantastic. I hope the GAC's are as good as the Dunlops were bad.

JohnLX300

iTrader: (2)

The Dunlops were great for off-roading and wet pavement, I did do a lot of off-roading with my RX last summer into the fall. The dunlops made a differnce with the off-roading as my friends with thier AWD vehicles had the Goodyear integrity, they didn't do so well in the sand and mud. That was before I replaced my strus, tie rod ends, ball joints and sway bar links. I beat up the RX a lot before I did all the work. Now I wouldn't be doing that so much. But the dunflops were bad even before that. And the RX compared to a Jeep Cherokee Sport, handles just as well off-road.

JohnLX300

iTrader: (2)

********UPDATE******* After having new tires, it is obvious that my old tires were defective. The car is smooth now...extremely smooth, It now drives like a LEXUS!!!