Cracking rotors.

[LS1 TA]

I have drilled and slotted rotors on my TA, both front and back. This past weekend while I was cleaning my rims I noticed little cracks starting to form from the centers of some of the drilled holes. I was wonder what caused this and what I might do to prevent it. I am guessing it is caused by heat and stress and I can remedy the problem by laying off the brakes, but isn't that what those kind of rotors are designed for?

[Christopherrr]

Drilled rotors are notorious for cracking. There are several thread pretaining to this. I've never experienced it with my set, but then again, I'm not rough on my car. Cracking is caused by heat/cooling cycle. I know a lot of the guys on the board recommend stock blank rotors.

[ConElite]

What kind of rotors are they? If they are some cheap brand ones then yes, they can crack. Those things are suppose to handle the stress and wear of heavy brake in like Auto-x and things like that. Unless your stomping the thing every time you come to a stop, then they should not be cracking. Chances are your going to have to replace them before they crack even more and fall apart when your up to speed. Then you'll be in deep trouble.

[Craig 94 TA GT]

Cross drilled are notorious for cracking, as Christopher mentioned above. Even expesive Bear rotors go through this....which is why I wouldn't recommend cross drilled for a daily driver. Here's a write up on prevention, getting them "o" treated...http://www.ws6.com/o.htm

[dochidalgo]

Point is: Why some cross drilled rotors are good over 20-25k like my car set?
The basic fact is stated: the cross drilled rotors, even the expensive or from famous brands are prone to crack....then
the variable factor is the driver's braking habits? The enviromental factor where the car is daily driven?
Definitively I'll never install plain rotors in my car because the fail brake performance in rainy roads.
Someone would answer these questions?
I would like to know the answers..interesting matter...

Regards
dochidalgo

[Joe 1320]

I would be curious if the transmission has some bearing on the cracking of rotors. An automatic must hold the brakes at a stop where stick cars do not. I'm wondering if after heavy braking how much heat soak influences the tendency to crack. hmmm.....

[MunsonGTA]

alot of the auto-x guys recommend just slotted rotters, not drilled or drilled and slotted. i also think it's from the stop and go from daily driving that causes the cracks, the heating and cooling cycle as mentioned before. in auto-x the brakes don't get much of a chance to cool down because you're using them quite often.

the auto tranny idea might also have some influence as well. but then again maybe not, unless you're on a mostly flat road, even in a stick you're going to be on the brakes, or riding the clutch. i'd rather be on the brakes then burning up a clutch.

[97LT1Z28]

I'm extremely hard on my brakes - no cross-drilled for me . . . . .