Years ago, Rotors and drums used to average $80-$90, sometimes more, each at the local parts store or dealership. They were produced in the respective Country the vehicle was atleast produced in and either met, or exceeded factory quality units. Lots of people used to have their old ones cut & resurfaced, because that would cost about $10-$15 per. They were made of such good quality that you could do this once or twice before tossing them out.

Now, they can be had for as little as $10-$20 each, for almost any vehicle, from a local parts store. This is due to the fact that now, they are made in China, in places where they throw a chunk of the cheapest piece of metal they can get,into a computerized machine. An hour or three later, this machine spits out a whole bunch of rotors or drums. These rotors and drums just barely meet factory spec and standard, if they even do at all. Cuttin/Resurfacing them is not an option when your brakes are worn, because they end up with such a bad lip or wear mark on them that you can't cut enough off to get rid of it. They often come out of the box warped, or warp very shortly after install. Again, due to the poor quality & workmanship invested into them initially.

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Kent Christensen
Albuquerque
'07 GL320CDI, '10 CL550. '01 Porsche Boxster
Two BMW motorcycles

Ikchris,

So,whose the OE supplier to Stuttgart?

[Trick question: is there any Superior Quality Rotor,offered?]

(You guys do realize Kestas is a Forensic Automotive Metallurgist ?]

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'84 300SD sold
124.128

To confirm your claim about "bad right out of the box"...I will relate a story about a brand new 1989 Ford SHO that I purchased...

Both rear rotors were so bad that the wheel hub bearings squealed every time I stepped on the brakes..including the ride home from the dealer the day I bought the car. I finally dial indicated them myself, because they were giving me such a hard time about replacing them..."pads and rotors not covered by warranty"

To do this I trued the outer rotor on a lathe to .000", and measured the runout on the outside edge of the mounting face...much smaller than the rotor in diameter...I got 0.170" runout. You can imagine what the runout was if I trued the minor diameter and measured it on the disc face...maybe double this figure....The callipers and brake pads would prevent the disc from wobbling too much, but the force caused by this deviation was actually flexing the axle shaft, and stressing the tapered roller axle/wheel bearing..causing the squeal.

With new rotors the sound went a way...but at 70,000 miles the right rear axle shaft snapped..while I was doing 75 mph on an interstate highway. An inspection of the sheared axle assembly showed heat blueing all around the failure point, which would have been where the center of the flexing took place.

The left rear had the same issue but not so bad..0.070" runout measured the same way (at the outside of the mounting face..ie minor diameter) The left rear had not failed before I finally sold the car. Never assume that because it's "OEM" that it's right...however the odds are still better that it will be more frequently than aftermarket stuff.