Shimmy at higher speed rates when apply brake


#1

I have a 2004 Lexus RX 330 with ~75K miles. It starts to shimmy when I apply the brakes firmly. Though it may shimmy at lower speeds, I only notice the shimmy when I am going over 55 mph. I specifically had the brakes checked by the dealer when it had a 70 mile check and they were fine. Any ideas on what might be causing this problem?


#2

have the rotors resurfaced and replace the brake pads.

should solve the shimmy when braking.


#3

Thank you!


#4

It is possible that the rotors may have to be replaced, rather than just being machined. Be prepared for that possibility.


#5

when has this had its last brake job?

my experience is to REPLACE not remachine or resurface the rotors. NEW. save yourself the hassle and headaches of turning them, and hoping they don’t warp soon after.


#6

I agree. Rotors with metallurgical irregularities that cause them to warp may tend to change shape every time they get hot, so turning them may be only a temporary fix. Better to replace the offending rotor and its mate and be done with it.

Our Lexus GS did the same thing with the original rotors, at about the same mileage.


#7

Are you also getting pulsating at the brake pedal ? If so you could have a faulty ABS sensor or tonering.

If the pulsating is only through the steering then rotors are the favourite candidate, I’d thoroughly check the steering and front suspension while your under there, any worn components will amplify rotor shimmy being transmitted through the steering system.

Also check the 2004 Lexus RX330 TSB (Technical Service Bulletin) 00404 (NHTSA 10008391) related to steering vibration.


#8

Did you get new pads recently? If so, did the mechanic explain how to bed them in properly, it varies from brand to brand. If they are new and you haven’t bedded them in, then ask you mechanic for the bedding procedures. If he can’t answer the question, then ask what brand of pad was used and google for the bedding information from that manufacturer.

If they have been bedded or you have several thousand miles on them, the try one or two moderately hard 65-10 stops in a safe area to do so. Don’t stop completely, just down to about 10 mph. Do not lock um up either, that won’t help. After the one or two decelerations, drive for awhile to cool the brakes. This should clear up the shimmy for awhile. You may have to do it about every 5k miles until the pads have worn down some.


#9

Please pay attention to your braking habits. Sometimes the heat generated that is warping the rotors are from improper braking techniques and peoples habits change without being noticed until there is a problem.