Drum Brakes W/ Cutout On One Side

UPDATE: I emailed the manufacturer customer sevice and they came back saying this was a defect and not for mill balancing.

Has anyone ever recieved drum brakes with a cutout on one edge of the drum? I'm far from a brake expert, but I'm also positive this is not supposed to be here because the center of mass would be offset from the axle slightly. The weird thing was that it came this way on both drums and was a perfect match in the shape of the cutout. I went ahead and installed them because I had no other option at the time, but I noticed more vibration than I'm used to on the next day driving. I've already asked to get new drums shipped, but I have to drive with these on while I wait for the new ones to arrive. Any thoughts on if the uneven weight could cause any damage, and if there is any situation where the cutout would be an intentional part of the design? Your comments are appreciated!

 

Balancing cut?

 

I know that's a thing with disc brake rotors, but I didn't think about it with drums. I suppose that makes sense though. I'm just surprised my stock brakes didn't have one too. Unless toyota just had really evenly casted drums.

 

there is probably a weight tack welded on your old one.

 

Does it look machined or rough? If you run your finger along it and it feels smooth, it was probably machined.

 

It's for the balance. Nothing to worry about

 

I emailed the oe manufacturer (Powerstop) and they came back saying it was a defect. These are off a Powerstop OE 6-Lug Drum Brake kit that I bought on Extremeterrain.com

 

I have to admit. I would’ve never noticed. And I would have probably run them. I’ll be curious to see if the new ones have the same grinds.


Those look intentional to me.
Like balancing grinds.

 

I'm now also surprised they aren't for balance. Balancing grinds made a lot of sense. It's possible the customer sevice person I talked to never asked anyone on the engineering/manufacturing side and just said it was a defect. However, I do still feel a slight vibration I never had before at higher speeds which is what made me look into all this.

 

Guess who ordered a whole set last summer and never got around to installing them

Guess what I found?

Yes. They are PowerStop
And yes, I’ll be throwing them on just the way they are