Ok, my rotors are now warped, but I got 40K out of them. I was always careful when rotating, and cleaning. My Nissan rep, who has always been up front with me has told me that they have fixed the warped rotors by upgrading the hardware(shims, etc..) has anyone had any experience with this?

 

warped rotors are so common in a lot of FWD cars. Shims really have nothing to do with the rotor. Shims hold the pads in place properly. The only way I can see a shim causing a problem is if it binds and holds your pad against the rotor causing it to heat up while you drive. This would also cause your pads to ware out very quickly. If your not having any rubbing, squeeling, or any other brake problems, just resurface your rotors. Your lucky you got 40K out of them. I only got about 22K when mine warped, and again about 12K later. They've been very smooth since then, but the next time I feel the pulse, it's upgrade time, Brembo here I come.

 

my service tech told me that the old shims were to fat and actually trapped heat which in turn was a factor in the warped rotors, so njmax you are partially right, thx for the info. He did however say that since Nissan has gone to the thinner shims about 6 months ago, he hasn't seen a problem since. Now maybe that is just because 6 months isn't really enough time for them to warp. I am keeping my fingers crossed, but if they warp again I will go the aftermarket route too.

 

Hmmm funny.. the shims aren't supposed to disperse heat.. they're supposed to absorb the tiny vibrations that cause noise, and hold the pads in place. which is why they use copper in them.. it's great for that stuff.

the rotors themselves are what are supposed to dissipate the heat, and the pads/calipers aren't supposed to gain much heat in an ideal system.

of course no brake system is ideal, and the pads & calipers will get hot..
but the warping of the rotors isn't caused by any of that. it's caused usually by bad driving practices. If you heat up a set of rotors ont he highway or hard driving in town, then stand on your brakes at a stoplight, it will warp the rotors because you're holding the pads against a small part of the rotor so it can't cool at the same rate the rest of the rotor is.
combine that simple problem with hundreds of stops in a week, and you can see why rotors get warped.

the other big problem is that people drive like bats out of hell, then park the car and let them cool over time. same deal. the pads are still against one spot of a hot rotor, the the rest of it cools much faster than where the caliper is covering.

that's one of the many reasons why you have cool-down laps on a race track.

 

I've had rotors warp from service departments putting on lugnuts too tight. OEM rotors from one of the big-three (think blue oval...) are notoriously crappy and will flex from the pressure of the rim pressing on them. The original Contour service manual actually called for lugnuts to be torqued to 62 ft/lbs. 62! I can go tighter than that with a 6" wrench.

I believe Nissan OEM rotors are of much higher quality. I've got 47k on the original rotors and pads, and I'm just starting to have pulsation. Regardless, I still ask the service techs to torque my lugnuts by hand, not with the air wrench.

Aside from high-end aftermarket rotors (Brembo, etc.), who makes a nice, durable rotor? I don't want gas-slotted or cross-drilled (keeping maintenance low), so what are my options? Nissan OEM, Bendix, Wagner, Beck, Napa?? TIA.

Regards,
TOM

 

Try cryogenically tempering them for warping resistance. Bill99GXE did this, and I did this to my transmission parts. Do a search on this forum and on the net for more info about it.

 

there are other things that can cause warping, lets say you come from the commute to your house and wash the brake dust off, that could do it because you're changing the temperature of the rotors to quickly, when I race they say never to put the hand brake on because it'll warp the rotors for the reasons mensioned above. but it really just depends on how your driving style is

Vinipux

 

I appreciate all the info and I am aware of the many aspects of how to try and prevent rotor warpage, and I have used all those things to my advantage, hence 40K out of my stock rotors. I asked all those questions to my service rep and while he agreed those things are helpful he still is adamate that the thinner shims will fix the warped rotor problem. Only time will tell, I hope he is right, I doubt it, but I hope.

 

I have nearly 70k miles on my stock Nissan rotors and they brake just fine. I've only had to resurface them once. One important thing is the method the rotors are resurfaced. I've had rotors on my other cars resurfaced and then pulsate again very soon. That's because the rotors were removed from the car when being resurfaced; so the rotors are cut according to the machine. But I've been going to another shop with an on-car lathe. Their machine resurfaces the rotor while the rotor is still on the car; so the rotors are cut according to the car. I haven't had any problems or pulsations occur again.

 

The stock rotors on my old GXE had over 100k miles on them and I only pulled them off because I bought some Stillen Sport rotors. BAD mistake. cracked in under 10k miles. put the stockers back on and drove harder on them STILL with no warping or cracking.

I even used them on my current car for a few weeks while my skyline rotors were on order after I ruined one set by using Hawk pads on 'em...
blah blah blah.. it all depends on how you take care of them.


As for other reputable brands, I would only suggest Brembo, OEM, and possibly Bendix. don't touch any other the other "mainstream" stuff.
Any of them should be cryo treated before installation. cost is $15-25 per rotor and only takes a couple days. the shop I take my stuff to drops the part on friday and runs it over the weekend, then they're ready on monday afternoon.