travelride

Does anyone else have what they would describe as squirrelly handling and steering with their IS when on uneven pavement at moderate speeds? Mine is actually an IS350C, but I don't think this is necessarily convertible specific.

By squirrelly, I mean it seems to want to go left, and go right, and left again, and do almost anything but go in a straight line at times. I've noticed it more on uneven in-town streets at moderate speeds than on the highway. As a matter of fact, the car seems to track just fine at 80mph on a concrete highway. But at 30-45mph in town it's a hassle to keep her heading in the same direction.

My car has Bridgestone Potenza RE760 Sport tires on it. They are all installed correctly, balanced well, and the tire shop says I have no alignment issues. I have asked the Lexus Dealer about it as well. Both the Lexus dealer and the tire shop blame the tire for the uneven pavement handling issues and say nothing is wrong with the car. I find it surprising though that these tires would have such high reviews all over the Internet if they were problematic. They consistently get close to 5 star reviews by everyone out there.

Anyone else care to impart some wisdom here? I'm about to change the tires even though they still have a good bit of tread left on them, but I'd be a bit peeved if I spent a good bit of money and ended up with the same thing continuing to happen.

Sffd103

iTrader: (16)

Ever think about sway bars?

firelikeiy

How many miles are on the car? Mine is starting to get a little squirrelly. I think the lower compression bushings need to be replaced on mine. I noticed one was cracking a while back. I have 90K miles.

getafewliv

I have been noticing it with my car lately too. I have also noticed a bit of a squeak when I get in and out of the car but haven't had time to really diagnose or deal with it. Now I am wondering if the two are related. I just figured my alignment may be a bit off since I was playing around with the ride height.

Gville350

iTrader: (10)

So would you describe the symptoms as the car would want to follow the ruts in the road, or is just generally loose on a completely flat pothole-free road? When those folks said the alignment is fine, did you actually have them perform an alignment or did they "eyeball" it?

travelride

In reply to everyone:

1) Just under 38000 miles.
2) I would say it follows ruts in the road more than any other car I've ever owned.
3) On perfect pavement it seems to drive OK.
4) The tire shop claims they put it on the rack, but they didn't have any paperwork to show me when I got back, so I wonder. I have an alignment policy on it. They may have been lazy and not done it since I'm not the type to sit in the waiting room and hang out for 3 hours. However, it doesn't behave like an alignment problem. Alignment issues tend to do the same thing all the time, right? -- pull left, pull right, etc. This seems to pull in whatever way it wants to at the moment in an unpredictable fashion.
5) Not sure what sway bars would do to fix the problem. Please help me understand.

Thanks!

hirsch2is

How is your tire wear? I had an e36 BMW that had this issue. Had bald tread on inner edge and tapered to about 50 percent tread on outside edge. It would wander a ton when there was a lot of road crown or when there were deep areas in the tar from cars constatly driving on it( think two valleys tire with apart from asphalt sinking over time). New tires basically fixed it. However with the profile of the tires these cars take you will never eliminate it completely on heavily sunken roads. I've also experienced customers cars exhibiting this from both worn bushings, lower ball joints, and strut mounts however with the suspension setup on the IS I would eliminate strut mounts.

valeoray

I too have the OEM Bridgestone Potenza on 17" rims. They would track like crazy on uneven roads. I'd say they are more than 1/2 worn. My 16" Hankook winters do not track at all.

https://www.clublexus.com/forums/is-...ramlining.html

travelride

Tire wear looks very even... With only 38k on the odometer and it being a Lexus would you actually suspect worn bushings or lower ball joints? Heck, I owned a Chrysler that had 100k on those parts -- and we all know how good Chryslers are built!

hirsch2is

i work with a former lexus tech. he told me expect new tires every 15-20k due to inner tire wear because they come stock with a ton of negative camber. and after seeing specs when doing an alignment on the is350 i just bought, they come stock with more negative camber than my e36 with a 1.5 drop. did you actually take a depth gauge to the tires. you would be surprised what a 3/32nd difference from the inside to outside can do. and this should be measured from about 3/4inch in from the inner and outside edge. hell i see camrys with 20k miles and no signs of curb rash with 1/32nd difference sometimes. I've also seen many cars come from the factory with out of spec alignments. also the isx50 does have a massive amount of negative caster compared to most cars so this along with wide wheels/lowprofile tires will all contribute

hirsch2is

and being a toyota tech for 5 years, which is pretty much lexus, and wrenching professionally for a total of 7 or 8, i wouldn't expect it but i would never ever ever doubt it. And ill tell you now some of the Mater techs at my toyota dealership without a doubt know more than the greener guys at the nearby ex's dealership. If you're under warrantee maybe mention to your dealer service writer to have an MDT(master diagnostic technician) look at it. they are the top of the food chain as far as techs go

andper10

I believe what you are experiencing is called tramlining. It is caused by the low profile tires and wide wheels. More info here: http://www.tirerack.com/tires/tirete....jsp?techid=47

The inner tire wear issue can be fixed by installing FIGS #2 LCA bushings:
https://www.clublexus.com/forums/sus...0-duro-hp.html
https://www.clublexus.com/forums/is-...eo-inside.html

travelride

Thank you! This sounds exactly like what's going on. Maybe I'll spring for these bushings... The people in the other thread, though, are talking about 70+k on the odometer. Mine is only at 38k. Are those Figs Bushings that much better than stock that you'd go ahead and pull the trigger on a pair of them to see if it alleviates the issue?

naveda08

iTrader: (1)

i have the same issue at 46K. Got the Figs lower arm bushings which helped while breaking but not much when driving 30-50mph. I switched over to Blizzaks back in Nov and it helped some but by now its starting again. Lexus dealer told me it was the tires of course but i know that is not the case. It feels like a rack and pinion bushing issue i had with my '83 corolla at 175k LOL