myov

My 2004 RX330 has about 75k miles on it. Over the past few months, I have experienced seemingly random episodes of severe shaking of the vehicle at highway speeds of 70+mph. It does not happen during most times when driving at those speeds. But when it does happen, the shaking starts out somewhat mild and then progresses to be severe enough to feel unsafe. Then the shaking will continue until the car is slowed down to under 40mph or so. I have also noticed that the braking of the car during these episodes is very sensitive and there is a noticeable pulsing in the brakes.

When I first experienced the shaking, I thought it was a wheel balance issue. I've had the wheels balanced twice since then and the problem still comes back on occasion.

Review of other posts/threads makes me think this may be a brake rotor issue.

Thoughts?

ToledoRX

Sounds like warped brake rotors. The steering wheel and seats starts shaking intermittently when braking between 50-70 mph.

nwfsnake

Pulsing when braking is normally a sign of warped rotors, but the vibration at high speeds could also be worn inner CV joints. Good luck!

Citronlemo

I no longer have the car but was repeatedly replacing the brakes rotors, brake pads and brakes themselves due to shaking when applying the brakes on my Lexus RX 350. Lexus was telling me that I was riding the brakes too hard and while I really liked the car, I ultimately I got rid of it due to expense and the hassle of having it repaired. I am once again seeking another car -- would love to get another Lexus. So i googled the issue, and discovered many, many others have experienced the same issue on this and other models and received the same reply. I am shocked to see that Lexus continues not to acknowledge and/or fix this issue. Wondering what can be done to light a fire under them?

PukeLexus

Get the Rack and Pinion checked ASAP. 2004-2007 RX vehicles are notorious for bad rack and pinion. The Rack and Pinion and Power steering on my 2006 Lexus RX was replaced before it had 50K miles.

ne0tekk

I have the same problem and just replaced the pads and rotors. Have not yet taken it on the freeway but going up to 50 miles seem to be okay so far. I noticed that the control arm bushing was cracked on mine but may need to take a look at the Rack and pinion if it's still shaking violently when braking at 70-80mph. Do we inspect for torn boots and leaking power steering or is there more to it?

PukeLexus

Yes, look for torn, melted, or cracked boots on rack and pinion. If you see any of these signs, the rack and pinion will eventually have to be replaced. While you are inspecting rack, look at the stabilizer bars on each side of the wheels (if original, they are thin gold bars). My stabilizer bars were replaced at 78k miles because they were leaking at the end rubber washer.

Power steering: A couple ways to notice power steering problem; With the car turned on, listen for high pitch squeal as you turn the wheel. Also, check your power steering reservoir and make sure it has correct measurement of fluid. The power steering on the RX330 is a closed system, so the only way to have a leak is at the reservoir or one of power steering hoses. If a hose or reservoir is leaking, just replace which ever is causing leak and add power steering fluid to recommended level. If you have a power steering problem, it won't make your car shake like bad rack and pinion, it will just squeal until the pump finally dies. If the pump dies, you won't be able to steer the vehicle unless you have the strength of the Hulk. BTW - If you do have to add power steering fluid, you need to use DEX, not just any old power steering fluid you can find at an auto store. Dex is a transmission fluid (read about this in your owner's manual). VERY IMPORTANT!

Back to rack and pinion: If you just changed your brakes and rotors, and your car is still shaking when you drive, you should NOT be driving until your rack and pinion is checked. The rack and pinion does not usually shake the car until it is ready to go. If it goes at high speed, that's a huge accident in the making.

ne0tekk

Great, thanks for that info. I noticed the passenger side rack and pinion boot was leaking and/or torn. Also the power steering fluid level was low so I topped it off with the Maxlife ATF which I also used for a drain and fill as recommended in this forum. I'll be taking it on the freeway today and if it's still shakes at high speeds, I'll definitely get the rack and pinion replaced. Thanks again!

Edino

Our 2017 RX350 with 13Kmiles shakes sometimes while applying the brakes. But I have narrowed it down that it only happens after the weekly car-wash or after a very humid night. After some driving and moderate braking, the brakes do not shake anymore. These rotors very easily rust when in contact with water or humid air. While I am washing the RX, I see the rotors getting light brown already; surface rust... I also wash myself our 2018 Silverado, and have no surface rust at all on the rotors (or shaking brakes).

I blame the shaking to the rotor material Lexus is using....

cdmn

Isn't shaking caused by warped rotors?