Rotors

[Unobtanium]

I'm certain they use those measured ratchets that ensures the proper poundage of torque.


I typed this up on my Smartphone using Tapatalk [emoji12]

I bet they used a pneumatic wrench and just let rip, unless they do things differently in Germany by far.

 

[boandlkramer]

They torqued it down and then used a Hand tool, I sat and waited the last time because my wife had an appointment elsewhere.


I typed this up on my Smartphone using Tapatalk [emoji12]

 

[CX-5um]

Could the lack of wheel balancing (wheel weights) cause irregular rotor wear?

 

[piotrek91]

Not re-tqing will not cause this unless the lug nuts actually come truly loose. OVER-torque is what bends rotors/hats.

As I understand it, uneven torque is what usually does them in.
Geeze! Looks like your 370Z had it really really bad

In the old days, star-pattern tightening using torque wrenches was the only way lug nuts were tightened. Not any more. Today, it is throw the tire and wheel over the lugs, hand start the five lug nuts, then use an air wrench in a once-around circle pattern, and you are done.

Doing this, the first few wheel lugs lock the rotor into location while the last few wheel lugs pre-load the rotor, which is like slightly bending a spring. Even worse, even if perfectly tightened to 100 ft-lbs, the last few lugs are false readings. Some of the torque is absorbed in flexing the rotor, not tightening the lug. This is almost guaranteed to cause uneven rotor wear (incorrectly called warped rotors), which results in the tell-tale pedal pulsations after just a few thousand miles.

The unevenly torqued rotor, even with the correct amount of torque, will not be bent when the rotor is cold. However, as the rotor heats up in normal use, it will expand unevenly. The most uneven area will, of course, be near the first tightened and last tightened lugs. As the rotor heats up and expands, a runout will be caused, i.e., a high spot on one side and a high spot on the other side. These high spots will come into intermittent contact with the retracted pads during normal driving, i.e., without brake pedal pressure.

As this happens, the semi-metallic pad used with police cars will grind away the high spots on either side. On the other hand, the ceramic pad used with retail cars will transfer material to the high spots. In just a few thousand miles, the rotor will have a significant thickness variation, either from worn away rotor or material transfer from the pad. Rotor thickness variation causes brake pedal pulsation and steering wheel vibration!

source:
http://www.hendonpub.com/resources/article_archive/results/details?id=1787

 

[GAXIBM]

Driving fast and having to do a quick hard stop will heat the pads to the point that when the wheel stops turning the pad material will be transferred into the rotor where the pad stops and creates a lump/high spot on the rotor which will cause the brake to vibrate on future stops. People call this warped rotors and typically turn them to fix. You can measure with a micrometer to verify. Some claim they can do a series of hard stops and get the rotor hot enough to level out the pad deposits on the rotors and restore smooth braking.

 

[piotrek91]

Could the lack of wheel balancing (wheel weights) cause irregular rotor wear?

I imagine if your wheels are so badly out of balance you'd have bigger things to worry about than your rotors. (like your teeth fillings and suspension components)

 

[erhayes]

The CX5 has pads with noise makers to warn when the pads are worn to ~ 2mm. How does one get grooved rotors when they are making noise, and giving warning to replace pads before rotors are gouged? I fear the rotors on any vehicle will suffer the same problem. Ed

 

[Silv3rCX5]

No. who drives like that?!

https://en.wikipedia.org/wiki/Left-foot_braking

Looks fine to me. Rotors are soft cast iron. Anything that embeds in the pad or gets between the pad and rotor is going to do that. Even if nothing does, they tend to groove over time. It's no stress.

I hope so.

I have the same exact prob and side as yours. I took it to the dealer and the service person told me to bring it in before my 1 year is up to get it covered through warranty.

if you drive next to a tall wall and brake you can hear a rotational noise coming from the driver side rear. The tech noticed it and said the can cut the rotor (which will reduce the life) or just get it warrantied before the 1 year is up

Good idea!

 

[Ram4Sam]

The CX5 has pads with noise makers to warn when the pads are worn to ~ 2mm. How does one get grooved rotors when they are making noise, and giving warning to replace pads before rotors are gouged? I fear the rotors on any vehicle will suffer the same problem. Ed

When the wear indicators start to squeal, time to replace the pads. If they start to squeal and you keep driving for a few more weeks, then the brake pad rivets will groove the rotors.

Sam

 

[Unobtanium]

They torqued it down and then used a Hand tool, I sat and waited the last time because my wife had an appointment elsewhere.


I typed this up on my Smartphone using Tapatalk [emoji12]

Well then I doubt this is the problem, and damn that's a precise dealership!!!! Nissan destroyed my rotors multiple times via pneumatic wrench, and the toyota dealership a friend worked at didn't even bother with tq bars on their pneumatic.

 

[Unobtanium]

When the wear indicators start to squeal, time to replace the pads. If they start to squeal and you keep driving for a few more weeks, then the brake pad rivets will groove the rotors.

Sam

Yep, and its unmistakable! Not a little squeak. A loud obnoxious dying rodent.

 

[Unobtanium]

Driving fast and having to do a quick hard stop will heat the pads to the point that when the wheel stops turning the pad material will be transferred into the rotor where the pad stops and creates a lump/high spot on the rotor which will cause the brake to vibrate on future stops. People call this warped rotors and typically turn them to fix. You can measure with a micrometer to verify. Some claim they can do a series of hard stops and get the rotor hot enough to level out the pad deposits on the rotors and restore smooth braking.

Yes and no.

On some pads, yes, for sure this is accurate. That said, my rotors were actually legitimately WARPED from how they were installed at the dealership. Getting them hot only caused expansion of course, which made the warp worse. With the material used for the pads on modern vehicles, pad deposits causing the problem is very unlikely, especially street driving. Most of the pads now on commercial products are very high ceramic content, low dust, etc. Not very prone to it.

 

[bALLISTIC]

I only have one original rotor left (passenger front) and on my third set of rear rotors..at 38k .The engineers that chose this design of calipers should be absolutely ashamed ..

 

[boandlkramer]

The good news? I'm closing the deal on a new Austin Yellow BMW M4 this week, all packages/options. (breakn)

Here she is!

I typed this up on my Smartphone using Tapatalk [emoji12]

 

[piotrek91]

Here she is!

Very Nice! DCT or manual?
So many amazing roads to enjoy a car like that in Germany!

 

[boandlkramer]

Very Nice! DCT or manual?
So many amazing roads to enjoy a car like that in Germany!

DCT


I typed this up on my Smartphone using Tapatalk [emoji12]

 

[GAXIBM]

Yes and no.

On some pads, yes, for sure this is accurate. That said, my rotors were actually legitimately WARPED from how they were installed at the dealership. Getting them hot only caused expansion of course, which made the warp worse. With the material used for the pads on modern vehicles, pad deposits causing the problem is very unlikely, especially street driving. Most of the pads now on commercial products are very high ceramic content, low dust, etc. Not very prone to it.

I believe the poster was talking about 90+ mph on the autobahn.

 

[Unobtanium]

I believe the poster was talking about 90+ mph on the autobahn.

I've slammed on the brakes doing well over that by a large margin to no ill effect, in various vehicles. I faded the brakes BAD on my 1995 Trans Am (they were under-sized, it was a heavy car, they never warped). Besides, I doubt it's often one goes from 90 to 0 on the Autobahn.

 

[Tom 6-6]

How many times have you been behind cars with their brake lights on for no apparent reason? They are two foot drivers. It is not just older drivers. How about very nervous drivers on the Autobahn with unlimited speeds?

 

[Unobtanium]

How many times have you been behind cars with their brake lights on for no apparent reason? They are two foot drivers. It is not just older drivers. How about very nervous drivers on the Autobahn with unlimited speeds?

The prevalence of stupidity does not make it intelligence by democracy, lol