Hey guys,

Long time lurker, but new member and hopefully contributor moving forward.
I have an 06 RX 330 with 140k miles on it. Over the past year or so we've noticed that when the car is driven a few hours at highway speed ~ 65-70mph (almost 3 hours everytime) the vehicle starts shaking. The shaking will start vibrating and shaking slowly and quietly, then get worse and worse. The sterring wheel starts shaking significantly and the noise becomes extremely loud. The noise sounds like something is just spinning/whirring. When I engage the brake during this situation, the brake becomes very sensitive, much more sensitive than normal, and braking makes the shaking more violent. The steering wheel is also shaking and vibrating significantly during this.

We've noticed that if you pull over and stop the vehicle, turn it off, then turn it back on the problem disappears.
If I remember correctly as well it's harder to get the car to accelerate over 70-75mph once the shake starts.
So far, I've had the brakes, rotors, calipers, wheels balanced, all of those checked entirely twice. The mechanic used to be head mechanic/service manager for Toyota so he isn't a chump. He is also a friend of my father so he isn't trying to run up a big tab.
He is left head scratching because he can't reproduce the problem, it takes a few hours of driving to make it happen. In so far, all he can come up with to check next is the transmission. With the car only being worth 7-8k, not sure how much it's worth to spend an arm and leg on transmission. Anyone have any thoughts, how should I proceed?

Edit--Failed to mention, that if you intermittently pump the brakes during the shaking you can slowly stop the vibration. It doesn't always work, but many of the times if I just keep pumping the break with short jabs after about 10-15 hard abrupt brakes the shaking/vibration will slowly dissipate.

 

My guess would've been a slightly dragging brake caliper that heats up the rotor over the long drive. But saying it goes away by just by restarting the car doesn't make sense for that. Do do you have an infrared thermometer? I would keep it in the car and check brake rotor temps next time it happens.

Have you changed the transmission fluid since it first happened? If not, give that a try in case the old fluid's properties are deteriorating as it heats up on the long drive.

 

Replace your drive line fluids...given that it takes hours of highway speed to start the shaking, it sounds like it could be an issue related to heat in the transmission/differentials.

The fluids in the drive line exist to lubricate and control heat. If the fluids have degraded, they could get so hot that the diff/transmission malfunction.

 

For AWD, have you ever noticed this overheating A/T Oil Temp. warning light? (#12 in the first photo), from the RX330 Manual:

 

nope never had that light ever before

 

Front axles can wear out on these. Search the forums and you'll find at least a couple of people with vibration issues who did brakes, bearings, everything with no luck. Then replaced axles, problem gone. Have your front axles checked by a specialist.

 

I had this exact issue on the exact vehicle. Our Rx has 160k miles on it - The shaking was so bad at 75mph, we had to pull off the interstate. And if yours is this bad, don't let anyone tell you it is the rotors or the tires or you need to road force balance your wheels....BS. It is your front axles:

https://www.clublexus.com/forums/rx-...tion-help.html

We have a mild vibration now, and these cars are notorious for bad steering racks. I have had a new one in my garage for over a year just no time to swap it out and write up a DIY - and hopefully we end up completely vibration free. I will before summer is over though. I would suggest doing axles....if that doesnt fix, it's your rack, which you'll have to eventually replace anyway.

 

any idea what the front axle and steering rack run cost wise? Thanks so much for the info.

 

Have an inspections first, maybe at Toyota. They can put it up on the hoist and pull on the axles to check for play etc. I like my Lexus dealer, but I cringe to think what kind of numbers they'd come back with if asked for axles and rack. Rack failure is common on these, mine was done by last owner.

 

For me, steering rack was $1100 for a Maval unit and $1600 for a Toyota OEM unit. (this was at a shop that specializes in Toyota .. my guess, the Lexus dealer would have been in the low $2,000's).

I normally only use OEM parts, but for this, went with Maval. So far so good.

 

I have Lexus RX330 with similar issue. Toyota dealer did not find anything wrong with it.
Any other suggestions?