Do Drilled and Slotted Rotors Make Noise?

Drilled and slotted rotors make a lot of noise, but you can reduce the noise.

Vehicle rotors are available in various designs, including drilled, blank, and slotted. As an experienced engineer, I will teach you why drilled and slotted rotors are noisy. Understating this technical issue allows you to make correct decisions when choosing a drilled and slotted rotor for your vehicle.

In general, there is no doubt that all brakes produce a screeching sound as the pads wear down; that is frequently caused by metal-on-metal contact. Unlike other rotors, drilled-slotted rotors generate a rumbling sound when you come to a stop as a result of slot contact with your pads. The occurrence of rust in the drilled and slotted portions of the rotors only accentuates the noise. 

We will cover more detail below.

Do Drilled and Slotted Rotos Produce Noise?

There is absolutely no doubt that all brakes produce a screeching sound as the pads wear down; that is frequently caused by metal-on-metal contact. Unlike other rotors, drilled-slotted rotors generate a rumbling sound when you come to a stop as a result of slot contact with your pads.

The issue will not affect your brake safety: however, most people find it extremely noisy and unpleasant. When used on large vehicles, it produces excess noise that cannot be muffled by rolling up the windows.


Why Do Drilled and Slotted Rotors Make More Noise?

The major cause of noise in drilled and slotted rotors is the friction between the accumulated rust (in the holes and the slotted portions of the rotors) and the adjacent metal surfaces as the rotor spin.

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If the slots are not properly angled, that could result in noise. The slot and pad should meet at an angle to “ease” the slot beneath the pad.  And hence, rotors with slots machined on a diagonal to the rotational direction are seen.  slots should not be machined radially from the center.

Noise may be produced if a hole(s) in a drilled rotor is not chamfered and/or if something gets caught in a hole.


Can I Reduce the Noise They Make?

The best remedy for noisy drilled and slotted rotors is replacing them. Otherwise, you could as well just machine them to remove rust in the holes and surface of the drilled rotors.


FAQs

Can the Drilled and Slotted Rotors Stop Brake Pads from Torching or Glazing?

Yes. The design of drilled and slotted rotors aids in the disengagement of some pads from the glazing. If there is constant friction, the pad merges part of itself into the disc, resulting in a loss of performance. The slots on a rotor sever the connectivity of the pad, providing key momentary stops in contact that prevent the process from occurring.

What’s the Cost of Replacing Drilled and Slotted Rotors?

You can quickly find cheap rotors for around $60USD, and performance drilled and slotted rotors for around $150. Many rotors are priced as high as $100, including rear rotors, but you can find a good set of economy rotor blades in the $70 range. You should expect to pay around $90-$120 per blade for high-quality, expertly-made rotor blades.

However, you can save some money if you understand how to do the job yourself, but you’ll have to purchase new brake pads. Before replacing your drilled and slotted rotors, check if they can turn or simply resurface — you will save a lot of money.

Take a look at some of our related articles below.


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About Sam Orlovsky

b1d87d2ee85af3e51479df87928bdc88?s=90&d=mm&r=gCertifications: B.E.E.
Education: University Of Denver - Electric Engineering
Lives In: Denver Colorado

Electrical engineering is my passion, and I’ve been in the industry for over 20 years. This gives me a unique ability to give you expert home improvement and DIY recommendations. I’m not only an electrician, but I also like machinery and anything to do with carpentry. One of my career paths started as a general handyman, so I also have a lot of experience with home improvement I love to share.

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