Ever since I put on my slotted rotors it seems like it didn't take long for the wheel to start vibrating during the intial bite. I assumed it was poor break in and dealt with it, but I was watching Trucks! the other day and noticed they made a big deal about having them in the right direction when installing a set on a Tahoe.

So......could I have them going the wrong way? Which way should the slots face?

 

Look at the vents inside the rotor. If they come straight out then it doesnt matter which way the slots are going. The vibration you feel is pretty normal though.

 

Yes, look at any of the disks, top portion. The direction of the groove should point toward the back of the car, scraping dust from the pad toward the outside of the disk. 'Burnishing' (break-in) is different for each manufacturer but 10 or so, 30-0 MPH quick stops, with 1-2 minute cooling in between should break-in the new pads. My D/S rotors are noisier, with no vibration.

 

As Dubbya said, it's the vent vains down the center of the rotor that matter not the slots. If the vains are curved and you put them on backwards your rotor will not have any air flow down the center. That will cause them to run hot causing thermal pad transfer and WAM.... There's your vibration.

If the vains are straight the rotor can spin in either direction. It does not matter which way the slots go. The slots only let gas escape from between the pad and rotor. They also wipe the pad clean as well. Direction means nothing.

Proper cooling is the key to good, long lasting brakes.

 

I stand corrected. Let me know who many miles you get out of your pads. Tks.