Can you explain this?
The new rotor has the L marked on the side which mb part guys says its for the driver side,great.
I install it and the rotor VENTS are pointing BACK AND UP. On my old rotor the vents point forward and down which seems right so as to cool the rotor as it spins FORWARD,right??
And get this, on my OLD rotor there is a R stamped on the side where the NEW rotor has L on it????
Whats going on?
I took it back and the part guys said they sold me the right rotor for the LEFT driver side. BUT, when I install that rotor it spins and rubs the break back plate. My old rotor does not rub at all.
This is weird, any suggestions as to what may have happened?
BTW, I was having problems with my rotor as it was causing my steering wheel to shake above 40 mph. It also was making some loud noise after driving the car alot. I thought that the rotor was warped.
BUT, after taking the whole thing apart (including the hub which holds the wheel bearings) and putting it all back together again the issues I had are GONE!.
I drove it hard and alot yesterday and even took it to the highway at 50-70 and no shakes. Got off the express way and no noises at all. Before, 2 minutes on the express way the rotor would make all kinds of noises as if the rotor was warped and rubbed against the brake pads.
So I'm really glad I took the whole thing apart. But soon I will be needing to replace the rotors and want to know whats going on with the above?
i just bought a set of rotors myself, i can verify the venting pattern, etc. later tonight when i get back home ...
Please do check the direction of the vent and let me know.
Thanks!
Last edited by myc43amg; Apr 8, 2008 at 12:47 PM.
ultimately i know that it doesnt matter, bc i have one of each, and ill just mount them to match the old ones i have on there now, but i am just as confused and curious as you are!
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The new rotor has the correct oriantation.
You'd be better of not changing the rotors back to the proper direction until you replace them as they look pretty worn on the pic, best not change the rotating direction so late in their life.
Just to confirm, the picture is of the left hand side when you are sitting in the car. (i'm used to RHD, just making sure)
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ultimately i know that it doesnt matter, bc i have one of each, and ill just mount them to match the old ones i have on there now, but i am just as confused and curious as you are!
The driver side OLD rotor thats on the left side of the picture is marked R. I believe it SUPPOSE to be L for driver side. That is what the NEW rotor from the dealer had stamped on it L NOT R like the old rotor. The new dealer rotor I believe had the part # 210 421 18 12,again with the R stamped on it.
The new rotor has the correct oriantation.
You'd be better of not changing the rotors back to the proper direction until you replace them as they look pretty worn on the pic, best not change the rotating direction so late in their life.
Just to confirm, the picture is of the left hand side when you are sitting in the car. (i'm used to RHD, just making sure)
Also, according to what you state "Your original rotors have been installed incorrectly." I think not unless the vents are suppose to spin where they will NOT catch the air as it spins forward. That is what the old rotors are doing, they catch the air as they spin forward. The NEW rotor once installed will catch the air when the tires spins BACKWARDS.
You wrote "Just to confirm, the picture is of the left hand side when you are sitting in the car." Yes, when sitting in the car its the left side. I always just tell the sales guys DRIVER SIDE or pass side, so nothing gets confused.
This is really weird, I wish someone would take a peak and see which way the vents face to catch the air. That will answer my questions and solve the problem. I believe the rotor I bought was stamped wrong, was suppose to be for the passenger side and not the drive side.
But until someone confirms the vent position I will not know. I'm going to check the passenger side to see whih way the vents are pointing.
The don't "catch" the air from the outer side, they actually "release" the hot air through the outer side. The air is drawn in through from the inner side. The flow of air is aided by centrifugal flow which is why a "normal" rotor with straight vanes can still cool itself.
the rotors from brembo rotors on my wagon's bbk have the internal veins swept backwards, inside to out. how ur old rotor looked
'Ausmbtech' - I like that 'catch and release' analogy


Last edited by StapleGun; Apr 10, 2008 at 08:01 AM.
So guys let me ask this as simple as I can.
Do the holes in the middle of the rotor point down like my old rotor on the left (see picture above). Or are the holes suppose to point up like the new rotor on the right? OR are you saying with your explanations that it does not matter which way they point??
This is for the driver side.
This is all I need to know, why cant someone just confirm this by taking a quick look at their rotor. You DONT need to take the wheel off. Just slip your hand and feel which way the holes are pointing (when car is cold of course).
Thanks.
Last edited by myc43amg; Apr 10, 2008 at 12:11 PM.
the rotors from brembo rotors on my wagon's bbk have the internal veins swept backwards, inside to out. how ur old rotor looked

the veins are supposed to be swept back. here is a pic of my brembo rotors. it is for the right side. u'll notice the veins are swept back, but the slots are actually swept forward, just as those described in the stoptech on the bmw forum link above.

if u'r old rotors were going the opposite way, then they were incorrectly installed.
Last edited by steve s; Apr 11, 2008 at 03:31 AM.



