Lynzoid

decided to post..
well, i have subj... it comes and goes.
sometimes it starts around 80km/h, sometimes around 110km/h.
tried 3 sets of rubber (but same wheels - oem), had my steering rods and ends replaced, alignment done twice (all great), numerous road-force balances,
just recently i got new rotors and pads all around, suspension does not have extra noises, had f/r stab bushing replaced as well as steering rack bushes... all oem.
so i'm lost totally.. wobble may be there one minute and gone another.. played with pressure in tyres...
i'd say it amplifies when turning right at speed AND returning wheel back to center...
also to notice, the feeling of the road in wheel AND floor is somehow harsher than before, it may even have coincided with beginning of the wobble (2m ago).

my ideas now (lost):
1. lower control arms, bushing there and lower bj.. it all feels tight, but lower control arm's FRONT bushing (non replaceable) is cracked. but getting new control arms is not easy decision... and wouldn't it be constant if it was it ?
2. alloys... they had been repaired 2-3 times each, but balance ok and road force shows no more that 5lbs axial load per wheel. possible ?
3. front struts (i have airsus). but i dont think it's them - on good roads it works great and dampens small potholes without any noises etc...
4. i read over here while browsing the forum, that one member had this issue and it turned out to be tire slipping on the rim.... i'll make a chalk guidemarks tomorrow.

Car is '01 euro airsus.
Any input appreciated.
Thanks guys

Bon

Which suspension components have been examined or replaced?


How about #48655?

yuri.ber

iTrader: (7)

Gosh.....Really?






























On the issue now. Does the vibration come at one speed and vanishes by another, for example starts at 50mph and ends at 70mph?

Lynzoid

Ok, 48655's have some surface hairline cracks, but still stiff and no leakage/visible sagging etc...
48620/48640 - these ones have bushing in them (where camber adjuster bolt goes), the bushing on left hand side is cracked slightly.
48610/48630 - solid and look like been replaced about 30k ago.

On the second reply - sometimes i can get clean acceleration to 160km/h without any vibrations on the way (and with new brakes also come to stop solidly with no wobble). Sometimes i can feel wobble at 90km/h and it just amplifies all the way up. Sometimes same at 110ish - wobble starts and just progresses. On some roads it's feelable at 60km/h (40mph).
I may have been noticing that road surface changes trigger that change, but i can drive on same road at 110 without any wobble, and next day on same road feeling it at 90 already...

I tryed 3 tire sets: first winters m+s, went all winter without a problem, then this starts; i get summer directional dunlops (new) - worse than ever, wobble at almost any speed; i sell it (the buyer is very happy with these on his inf g35x) and i get michelin primacy hp's (widely used on ls430 here). i do road force (hunter machine), drive out, have about 20km of wobble-less driving then it returns. i get back and re-do the balance. second time out it's there right from the start....
gosh darn it

ancdmd

My brother had this problem on his '01. Had it aligned several times, tires/parts replaced etc. Problem was a wobble on the highway, pronounced when in long sweeping curves. It was being caused by some kind of misalignment with the steering rack. Apparently the Lexus dealer had done some work on the rack, replaced the rod ends or something, and didn't properly center the steering range of motion before putting everything back together again. The car would drive fine for the most part, but this misalignment would cause the suspension to get thrown OUT of alignment when the car was being laterally loaded, thus causing the wobble. I don't quite understand what the exact problem was but I do know that an independent Lexus mechanic diagnosed it and had to disassemble most of the steering assembly (I think also remove the steering wheel) and put it back together correctly. Anyways whatever he did solved the problem. Let me try to find out more details.

ancdmd

here you go:

https://www.clublexus.com/forums/ls4...vibration.html

Bon

To check for off center steering rack you can simply set the steering wheel straight ahead and count the turns to full-right and full-left. (If you need to you can buy a $5 inclinometer at Ace hardware to measure the exact angle of the final turn). If they are not exactly equal then you've found a problem.

FWIW the LS430 does not have VGRS VGRS or Variable Gear Ratio Steering the steering rack gear ratio changes from the center to the full turn position. This is not to be confused with variable rate power steering which is a steering pump that provides less assist at speed. If a VGRS rack is off center when the car is aligned then as you turn the wheels one wheel is turned farther than the other and therefore they go out of alignment. Later LS460's, GS460's and LX470's have this but the LS430 does not.

Lynzoid

Yeap, i do not have VGRS, and turning to full left/full right produce equal amount of turns/angle at the end...

yuri.ber

iTrader: (7)

Do you have oem alloy wheels?

Lynzoid

yes, as stated in the first post. each had repairs done at different times.

yuri.ber

iTrader: (7)

I had a similar problem with my Lexus, my rims with 5mm spacers were sitting on the wheel pins and not on the hub in the front. After countless balancing and alignments I caught this problem, bought a $130 hub centric spacers and have been happy since, no vibration at any speed.
I also had a similar problem with my 2000 Chevy Impala. The vibration was unbearable after 25mph. After changing the whole front suspension within a month the vibration gradually lessened but was still there. It turned out to be a right axle than was bent a little. I changed it and no more vibration.

Lynzoid

Did not understood that at all.... Spacers ? I'm all oem... 'hub in the front' ?
'Hub centric spacers' ? Are you talking about fitting aftermarket wheels ?
Right 'axle' ? What do you mean by that ? CV ? right rear CV ?

yuri.ber

iTrader: (7)

I have Lexus wheels, but for a second gen GS. They do not clear my calipers so spacers are needed even thought the center hole is the same diameter as the hub.
Axle that goes from the tranny to the wheel (forgot what it's called) but that was a front drive car. I think it's a front suspension problem/alignment problem. Maybe a front lower control arm rear bushings (48655), since you already changed tie rods and steering rack bushings. Also, how many miles do you have on the car?

Lynzoid

Oh, gotcha on the spacers idea !
Yes, i call it CV axle, gotcha as well.
Ok, car just been on a lift.
What was done: replaced front and rear stab bushings (links are all ok), moved some lugnuts from front wheels to rear and back (yeap, going THAT crazy here); also i took a rather large prybar and 'tested' these four (both sides) lower control arm bushings - yes, they are slightly 'not new', but all four appear tight and no sagging there.
left lower ball joint have slight oil spot on the rubber joint cover.
So i decided to book bj replacement for tomorrow and i did just that.
Then, i drove out and took it for a short spin.
Wobble have not manifested itself even a little, tried up to 120km/h (85mph i rekon).
So, going to drive it some more today, but it feels like voodoo at this point...

Car have 207750 honest kilometers on it, and i take great care of it.

Lynzoid

Well, issue is gone nowhere.... Although with new stab bushings car definitely tightened up.
Will replace ball joints and post tomorrow.
Thanks for support gentlemen.