vb9594

My car is a 2008 LS460 SWB. I bought it with 69,000 miles on it, has about 75,000 miles now. Car has had a rear end vibration at speeds of 60 mph+ since I bought it. The vibration seems to lessen when I have a full tank of gas. So...I took it to my Lexus dealer. They put it on the lift and showed me how the two rear tires appeared to be slightly out of round and said that was probably the culprit.

I then bought winter tires and put them on. Still had a vibration. Was told to wait until I put all season tires on, then they'd start to pursue.

I put Pirelli P7s on yesterday. Seem like a great tire, but I'm still feeling a rear end vibration. All 4 wheels were road force balanced. I will be taking my car back to my Lexus dealer to see if they can diagnose. Any thoughts on causes of rear end vibration would be much appreciated. Wheels are not bent, BTW. Thanks for the help!

Rhambler

You have aftermarket wheels or OEM?

You try swapping the rear wheels with the front to eliminate out-of-round definitively? Bent wheels or rims could also be causing this and can be verified by simply swapping the front and rear. Assuming aftermarket, you running lugcentric or hubcentric?

Barring that, it could be the hub or suspension.

caha14

My 2008 LS 460L had multiple sources of vibration which my dealership and Lexus jointly addressed satisfactorily (and this is an understatement... my car drove better-than-new when they were all done).

One of those sources of vibration was the rear-end, and a new driveshaft solved it. They did also perform a TSIB for driveline vibration (number eludes me at the moment, but I've posted elsewhere and could share later, if you can't find it). Point being, there was a known issue affecting some '07, '08 (and maybe '09?) LS 460s.

For starters, which dealership do you use here in MA?

vb9594

I'm running stock wheels on the car. Haven't done the front/rear swap yet, but I figure that should probably be the first thing the dealer does.

I'm using Herb Chambers Lexus in Sharon. Caha- I think I've seen your driveline post before. I mentioned it to the tech at HC the first time I was in for this problem and he was dismissive of it (not in a bad way, just in a "that's highly unlikely" way). I'll try to find that TSIB, but if you have it handy and can repost, much appreciated.

General question: If it's the hub or suspension, where do we start looking? Are there any more common failure areas in the suspension that I should focus on?

Thanks for all the responses- very much appreciated.

vb9594

Caha- found the TSB but the link appears to be dead. It's this one, right? Not the link: L-SB-0147-08 (Abnormal Driveline Drone/Vibration Between 55-65 MPH)

caha14

Good point, and even better yet, a temporary swap with a set known-to-be-good (say, from a demo LS460) would work wonders at confirming or ruling out tire/wheel issues.

Statistically speaking, I imagine a small number of vehicles exhibited this condition. However, there is a reason a TSIB was published, so I wouldn't be so quick to dismiss without at least checking basics like driveshaft angle, etc., something that was actually off FROM THE FACTORY on my car.

TSIB is L-SB-0147-08. PDF I have is too large for CL (apparently), but let me see what I can do...

Interestingly, the TSIB includes some suspension work. I am not suggesting that this is, specifically, what Rhambler is referring to, but it's clearly part of the mix (even if the driveshaft is the big item - which, incidentally, TSIB calls for re-indexing, not replacement, except this didn't work on my car).

tbilisi79

Is the vibration worse when you are braking? I had this issue when my Gs430 had a sticky caliper and it warped one of the rotors out back.

Also a bad transmission mount will cause a good amount of vibration. It's easy to check if its worn out and replacement is really inexpensive and quick.
I hate to say this but by 100k miles our cars could benefit from a new set of tranny mount and probably engine mounts.
Check the tranny mount first.

vb9594

tbilisi79: The car does have a slight vibration when braking, but I've been assuming that's just a warped rotor...would a warped rotor cause a vibration at high speed? Thanks.

caha14

Generally, warped rotors in front will cause the steering wheel to shimmy when the brakes are applied; warped rear rotors will cause the vehicle to vibrate 'fore-and-aft'. What you are describing (at 60+, etc.) does not sound like anything related to brakes. It sounds like a harmonic vibration triggered by an out-of-balance tire, out-of-round tire or out-of-balance driveshaft.

vb9594

Hey caha14- one more question I was thinking about: Besides the vibration, are there any other telltale signs of the driveshaft being bad/out of balance? I'm just curious if you are aware of anything else. Thanks.

mdpresco

Does the vibration amplitude increase with increasing speed above 60 MPH or does it decrease?

Do the wheel swap first. Other possibilities include the flexible elements and/or the center support bearing for the driveshaft.

vb9594

Thanks. The vibration increases dramatically above 60 mph. Does that tell you anything?

caha14

Vibration is the ultimate sign of an imbalance. But again, you should have a known-to-be-good set of wheels and tires (like I said, ideally from a new demo) on the car to see if the vibration persists, and thus, it can be traced back to the driveline.

With my 460L, in addition to the vibration, when the Diagnostic Specialist at the dealership checked the driveshaft angle on the lift, he discovered it was off (from the factory, as I've said before), which only exacerbated the issue.

Yes, something is likely to be out of balance. Where do things stand with your dealership?

CRowe14

See, now this is something, well, an issue I've had for some time now.
I've had the following items done/performed:

-All 4 UCA's replaced with revised OEM arms (Lexus)
-Tires RFB 2 times in 1 year (1 @ Lexus, 1 @ Kauffman Tire)
-2 tire rotations (1 @ Lexus, 1 @ Kauffman)
-1 4W alignment (Kauffman)
-New pads and rotors a year ago

Once the suspension work, alignment and RFB were completed, the vibration was reduced but not completely gone.
Unfortunately, when I purchased the car, it did NOT have the OEM wheels on the vehicle.
I'm wondering if that is my problem.
I experience vibration at 68mph (used to be around 72mph) and once I reach 82mph and over, its smooth again.
I'm not sure if its from the rear of front.
All I know is that the passenger seat visibly vibrates and I can feel it in my seat, a very small bit in the steering and a small vibration in the gas pedal.
I'm not sure if its the LCA's, tires, which btw have 90-95% tread life left ( I do realize that new tires can be defective but no one has brought this to my attention in neither RFB situations), the non-OEM wheels, shocks (I'm non-air), hub...im clueless.

waynedog

I have had the exact same problem with my LS. Quick summary:
* purchased it 2 years ago (2009) CPO from dealer
* had exact same vibration. They RF balanced 2x but did not get rid of it. Checked driveshaft, etc and all looked fine
* car had nearly new Michelin Pilot Sport tires on it. They said it must be the tires and put a brand new set of Michelin Pilot Sport tires. Vibration did not go away.
* they talked to Lexus corporate and said there were lots of these problems and it was due to tires being slightly out of round and the LS suspension picks it up.
* they put a brand new set of OEM Bridgestone EL42 tires on car and vibration went away
* that was 20k miles ago. Vibration is now back (recently). These Bridgestone EL42 tires are not rated very high, but they did solve the vibration issue for 20k miles.
* now I am not sure what to do