I need someone smarter than me to point me in a creative direction...

Initially...I had a vibration in the front and rear. I Road Forced Balanced the tires 3x. Each time the new dealer or indy wouldn't accept that the previous shop was competent. EVERY TIME the tires/wheels were fine. Replaced on Front & Rear: Bearings, Rotors, Brake pads, and finally Front Control Arms. That seemed to fix the front vibration (although some "clunking" is starting to occur). I plan to pull the front and recheck, but I can't find through all my searching on a means to test whether a control arm has gone bad, other than visually if the rubber is torn. None of mine show signs of tearing or breakdown, but a closer inspection is now required.

I said the front was "fixed" relative to the vibration, but the rear continues. Occurs above 65+mph and is inconsistent. Control arms on the rear "appear" fine. Dealer wants $1K to evaluate Drive Shaft alignment that one of the other guys on this site said that he experienced. I want to check the box on other things I can do before that occurs. When I get to that level, then it's probably the sad realization that I need to get rid of this car. I love this car, but really really really need some help on what to check. I'm happy to do the work, but I'm sick of wasting weekends tearing the car apart with no resolution.

My logic...it occurs when high speed. I have tried to shift into neutral, and the vibration seems to remain, though discernably less. It has to be either drive axles, control arms, or possibly a drive shaft.

Any questions or ideas are appreciated, and yes I know I've been asking this for 1.5yrs if you look back, but I can't figure it out. So thanks for your patience with me.

 

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I'm no smarter than you, but would like to share an experience I had with my car vibrating at 60MPH or above. A few years ago, after a Lexus Collision Center took off my tires to repair my car's bumper, my car vibrated when my speed exceeded 60 MPH. Below 60 MPH, the car ran fine. I took my car to a tire store and they reported that the balance studs on two of the tire wheels fell off. After they balanced the wheels, the shaking/vibration was gone. So, since you have already checked and updated your car's suspension components, it may be worth checking your tire wheel balance and also if any of your tire wheels is out of shape (not round any more).
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He said he had road force balanced the wheels 3 times, so its not a balance issue...

 

For the rear vibrations maybe check for rust deposits where the rim meets the disc and the disc contacts the wheel hub.

I had a bad strut on the rear that really caused some nasty vibrations over certain pavement. The lower rubber bushings on both of my rear struts was also deformed from age. 2007 with 180k miles

 

Did that too. I take a grinder with a wire wheel to the rotor disc every time they come off, for safe measure. Thanks.

So been out there all day. Took everything loose to physically inspect it. What a pain in the ***. I can't find anything visually wrong. I have a slight clunking (barely noticeable until I started this ghost hunt) coming from something on my front driver's suspension. That's great. All the front upper/lowers were put in new March 2019. I tripled checked the angles, torque, and damage. Nothing. They are Mevotech and come with a lifetime warranty, so now I get the joy of taking it apart again for...let's see...the 9th time? That is if I can figure out which one. I really don't want to buy a Chassis Ear for $569. I heard some guys had bought microphones and ran them to each of the arms and recorded the changes in sensitivity. Research problem #124.

The rears seemed fine. I followed the Lexus ball bearing test https://workshop-manuals.com/lexus/l...pecifications/
Not sure I'm doing this test correctly, as they all seemed to turn fairly freely to me and I couldn't see the point. I guess if you had one lose it's grease and lock up, but I can't tell if the ball is soundly in the socket or just a 1/16" out of play. Whatever I'm exhausted.

My tires could go for another 5-10K miles, but I need new TPMS sensors in two of them, and I wanted an excuse to go to a black set of wheels. DiscountTire.com seemed the most fair for a package deal, so I went ahead and ordered a new set...and yes I paid for the Road Force Balancing again. I am undoubtedly the most balanced person I know right now. Not the most sane, just throughly balanced!

My wife can't understand why I won't just sell this car, but I had to explain that if I buy a new LS, then my daughter's wedding would have to be moved to an elopement. She told me to get my *** out there and don't come in until I fix it. Yes Ma'am.

So, still here welcoming help.

 

Could be rear axles/inner cv joints. Can you put the car up in the air and have someone put it in drive while you watch the axles, drive shaft, etc? Be careful, obviously. It would be even better if you could do this without the rear suspension hanging...support the rear control arm up, while it’s in the air...bottle jack/tranny Jack. Let those wheel spin, get a flashlight and check for something that doesn’t look right.

Vibrations are tough to pinpoint. Replacing some components will mask the situation until that vibration wears right through those new components.

 

Some questions/thoughts:
1. When you say the vibration is inconsistent, does that mean that it is sometimes absent, or that the vibration itself fades in and out or has varying intensity? A driveline misalignment will create a vibration with an overlay of varying intensity, like rrrrrRRRRRrrrrrrRRRRRrrrrrrRRRRR...
2. Driveline alignment means that the output shaft of the transmission(RWD)/transfer case(AWD) is exactly parallel to the rear differential pinion shaft. They can be at different heights, but they must be parallel.
3. On my AWD car, the rear trans mount and front differential cushions had sagged, so that the transfer case shaft was out of parallel to the rear diff pinion shaft. The resulting vibration had varying intensity, and was worse when coasting - and especially bad when coasting downhill. This is because the car pushing against driveline drag causes the pinion of the rear differential to rotate downwards, worsening the misalignment caused by the sagging. The vibration lessened when I bumped into Neutral, because that lessened the total driveline drag by decoupling the engine from the driveline. Conversely, accelerating makes the pinion nose want to rotate up (reaction force to the rear wheel rotation direction), which reduces the net misalignment and resulting vibration.
4. If the pinion nose is too high, the vibration will be better when coasting and worse on acceleration (since the nose moves higher on acceleration).
5. There are selective spacers above and below the front differential mount cushions that can be used to adjust the pinion angle, depending on the nature of the vibration.
6. On a 2007 it is likely that you could benefit by replacing the trans mount. That one thing may fix your problem.

 

https://www.ebay.com/itm/Genuine-Lex...-/153481420292

 

When was the last time your diff fluid was changed? If it is bad, it could be your diff bearings causing the vibration. The diff fluid should be changed every 15k miles or so. Also, check the transmission mount. My GS300 had a vibration at speed when I bought it. I immediately changed the trans mount and it went away. I could tell that's what it was when I got under there to look. Used the same mount as all of my Supra's and I could tell it was worn out due to how squished it was.

 

Hey guys, apologies for late response, but had company problem and had to jump on a plane. Flying home now, so reading these responses are great.

TEC80, I love the logic you relayed and the cost of the part is well worth rolling the dice and trying it. I'm going to look at the procedure now. I've tested shifting into neutral at high speed, and my experience is almost IDENTICAL to your description. I would notice it more on rougher roads, and less on smooth new pavement. Sounds like I need to look into this component and report back.

Williamb82, I changed the diff fluid ~5K miles ago. Sounds like the conferring is centered around the transmission mounts and I plan to investigate and report back.

Thanks guys,

 

OK, Great News and Bad news!

Great news is that changing out Transmission Isolator seems to have fixed my vibration issue. The new tires have added to the better ride as well.

SHOUT OUT to Tec80 and Williamb82 for the tip above, as it was SPOT ON! Thanks guys!!!

Bad news, is that I think my Front Lower Rear Control Arm (placed new in service March, 2019) has a clunking noise and upon inspection, looks like the bushing where the air shock connects is deformed or "squished" compared to the other arm. No worries, they have a lifetime warranty and I'll be ordering a replacement from RockAuto following this post.

Also, I can't seem to load the TMPS sensor ID's for the new tires. I get an Initialization error and telling me to cross TC & GC on DLC3. OK, don't have a clue what the hell that means, so it's off to study some more.

Always, something

 

 

Anyone know the part for AWD cars? The link to ebay says the part is for non-awd cars. I've noticed the slight vibration at highway speeds recently and was thinking it was time for new suspension bits - tie rod ends and ball joints. This would be a much easier fix. Thanks.

 

Read up on putting load on the arm before final tightening