Steering Wheel Vibration 80-60 Mph On Braking/decel

[chopper20]

I have seen this topic. I know the standard reply is rotor warpage. There has to be something else. My 98 GS 300 has 60k miles, had vibration through steering wheel on braking. Rotors were warped. I replaced the fronts with Brembo crossdrilled, and the rear with Brembo stock. On first braking at the described speed I still get the shutter. Has there been a campaign by Lexus to fix this. I see it is a common complaint.. Frustrating--stops real good now though.

[DaSwede_420]

I have seen this topic. I know the standard reply is rotor warpage. There has to be something else. My 98 GS 300 has 60k miles, had vibration through steering wheel on braking. Rotors were warped. I replaced the fronts with Brembo crossdrilled, and the rear with Brembo stock. On first braking at the described speed I still get the shutter. Has there been a campaign by Lexus to fix this. I see it is a common complaint.. Frustrating--stops real good now though.

just curious how much did you get all your brembo's for? Not sure how to fix your vibration, try everything though, change your pads a few times, check allignment, brake fluid and all. I was talking with a friend who said there was a valve that distributes the brake fluid in the lines "relatively evenly" to the different brakes, maybe the split valve is not calibrated right or malfunctioning (which is supposedly computer controlled on lex).

Good luck

[GuyTelefunken]

Just because you replaced the rotors, doesn't mean they are properly seated on the hubs. To correct this condition, assuming alignment and tire balance is correct, try the following. I'll be referring to the fronts primarially because it is here that most problems felt through the steering wheel come from. The procedure for the rear is the same.

Remove the rotors. Clean the hub face of ALL rust and scale. Wire brushes, rotary wire brushes, sand paper, a cold chisel and hammer, and/or whatever else it takes to remove every speck of crud. Remount a rotor using 3 nuts skipping one stud between one pair or nuts and the remaining nut. Basically, nut-nut-skip-nut-skip. I find it helpful to use stacked flat washers under the shoulder of the nut between the nut and the rotor face. Lexus wheel nuts have a chamfer on the side towards the wheel which I feel should never be put directly against the flat rotor surface. Use the washers or other suitable spacer at your own discretion.

Follow the directions for indexing in the attached .pdf. I usually mark one stud (with a sharpie) and mark the runout at each of the five rotor positions on the rotor center hat in reference to this stud. You will be surprised at how each rotor position gives you a totally different reading. When you have found a position with the least runout, mount the rotor in that position. Check the runout again to make sure it is within specs.

Remount the wheels and torque the wheel nuts to 76 ft. lbs. If all goes well, enjoy the smooth ride that will follow.

Indexing_Rotors.pdf

[chopper20]

Just because you replaced the rotors, doesn't mean they are properly seated on the hubs. To correct this condition, assuming alignment and tire balance is correct, try the following. I'll be referring to the fronts primarially because it is here that most problems felt through the steering wheel come from. The procedure for the rear is the same.

Remove the rotors. Clean the hub face of ALL rust and scale. Wire brushes, rotary wire brushes, sand paper, a cold chisel and hammer, and/or whatever else it takes to remove every speck of crud. Remount a rotor using 3 nuts skipping one stud between one pair or nuts and the remaining nut. Basically, nut-nut-skip-nut-skip. I find it helpful to use stacked flat washers under the shoulder of the nut between the nut and the rotor face. Lexus wheel nuts have a chamfer on the side towards the wheel which I feel should never be put directly against the flat rotor surface. Use the washers or other suitable spacer at your own discretion.

Follow the directions for indexing in the attached .pdf. I usually mark one stud (with a sharpie) and mark the runout at each of the five rotor positions on the rotor center hat in reference to this stud. You will be surprised at how each rotor position gives you a totally different reading. When you have found a position with the least runout, mount the rotor in that position. Check the runout again to make sure it is within specs.

Remount the wheels and torque the wheel nuts to 76 ft. lbs. If all goes well, enjoy the smooth ride that will follow.

Thanks for the detail. I only have a couple hundred miles on the new discs and pads, so I will redo with the your prescribed procedure. Thanks for taking the time!