Measuring Run-out on Miss Daisy's rotors

ultane · 2026-11-07T15:02:04-0600

I have mentioned more than a few times on this forum of the horrible 5K service that I experienced at a Toyota dealership in Ocala, Florida while my GF and I were traveling a couple of years ago.

The worst thing that I saw (I watched the entire service from the garage door) was when bubba was rotating the brand new Michelin LTX tires. He ran down the lug nuts with his air impact driver in a circular fashion, and upon getting them tight, he continued impacting them for what seemed like an eternity, in reality, only about 5-7 seconds.. it was all I could do to not run over there and take the air impact wrench away from him (and beat him with it

). Instead, I calmly asked him how many foot pounds of torque his impact gun tightened the lug nuts. He proudly boasted, 250 foot pounds!!! He then took out a torque wrench and re-torqued the lug nuts, again in a circular fashion. I asked him what he was torquing them to... 93 foot pounds he replied

I left that dealer and drove 4 miles down the road and bought my 5th torque wrench and a 21 mm socket, and retorqued the wheels right there in the Lowe's parking lot.

Ever since that day, the OEM Michelin tires made a wawawawawawa noise going down the highway. Miss Daisy's brand new Bridgestone Dueler AT Ascent tires do the same, but at a different, lower pitch.

I recently learned that over tightening lug nuts can warp/bend the brake rotors.

I need to measure the run out on the rotors, so I can justify spending ~$650 to replace all four rotors. I already have a tool to do so (Horrible Freight).

Any suggestions on the best way to measure the run-out? I am guessing, put Miss Daisy up on four jack stands, remove the tires, and measure.

But I am not sure the best way to do so. I am guessing put her in neutral, and give them a slow spin, one rotor at a time??

Mopper · 2026-11-07T15:43:24-0600

Sounds like you're on it to me. I assume the opposite wheel will back-drive? If it does, that's how I'd measure, on the opposite side of where you apply the torque

Bad1975 · 2026-11-07T16:13:17-0600

Hopefully you got a dial indicator with a mag base and arm?

If so, the easiest way is attach the mag base to a magnetic piece within reach of rotor by the arm and set the arm up to where the dial is touching down on the rotor through about it's mid point of travel on the gauge. Then first find the high and low spots and then go to the neutral spots between and zero the indicator in that location. Measure the positive and negative deflection of the gauge and pay attention to how many degrees between the deviations from 0 to hi(+ deflection) to 0 to low(- deflection) and back to 0 again. Example +.010" through 120 degrees of arc and -.010" through 120 degrees of arc and note how big if at all the zero area is.

I'd take a reading outside, center and inside of the circumference of the rotor. You may want to remove the caliper to check the inside if nothing of concern is noted on the outside of the rotor. Believe the spec is .002"

Make sure you lock the rotor down with at least two lug nuts snugged up after removing the wheel or you'll get horrible results and also check for wheel bearing play. You can check the wheel bearing play prior to removing the tire easiest once jacked up by trying to rock the tire from top to bottom. If there is play there will be no point in checking rotor runout as you'll likely inconsistent results.

The degree of the deflection that occurs isn't real important unless your right up on the max spec over a large area. Just something I like to do to gauge how big the issue is.