[kaylorRN]

I recently replaced a noisy hub on my 2013 and those two screws were so loose I removed them by hand even though getting the rotor off required some persuasion. Lug nuts and rust were doing all the real work of holding things in place.

 

[jimmaki]

The caliper sort of holds the rotor in place, but it's hardly secure and subject to more movement if you happen to drag the wheel over the rotor on the way on or off. It might be "OK" to depend on it until you remember to put a replacement screw in next time you service the car.

Way beck when, in a business school example case, GM explains that a bolt or screw is something they need to design and spec, purchase, inventory, workflow to the line in the factory, then catalog, ship and inventory, distribute to dealers, inventory there, install under warranty when one fails. Times however many of that series cars are built. Bottom line: If there was a way to avoid having them the factory would have done so. With that in mind, I see no reason to leave them out. But that's just me.

I though everyone knew those screws are there in an asymmetric pattern to discourage rotor indexing. 🙃

 

[Allan Robinson]

How important are the 2 screws that hold the rotor to the wheel hub?

I just changed the rotors and one of the screws was being difficult so I had to drill it out. Do I really need to replace it or can I live without it?

The serve no purpose but if you want to keep them just remove them and add a small amount of lithium grease to the threads and reinstall them.