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2004 Cadillac CTS-V
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Discussion Starter #1
So I'm working on installing some RB rotors on the front and i've got everything mounted up now but the rotors are rubbing the inside pad some and there is a gap of about 2mm on the outer pad. It seems like the rotor needs pushed out about 1mm and everything would fit perfectly. Has anyone else experienced this before? Any help would be appreciated.
 

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04 CTS-V LS6
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104 Posts
AMorgan said:
So I'm working on installing some RB rotors on the front and i've got everything mounted up now but the rotors are rubbing the inside pad some and there is a gap of about 2mm on the outer pad. It seems like the rotor needs pushed out about 1mm and everything would fit perfectly. Has anyone else experienced this before? Any help would be appreciated.
Did you pump up the brakes? That should close the gap.is it rubbing bad or just dragging slightly?
 

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'05 CTS-V
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Mine were offset a bit, but not as bad as what you're describing. In a thread I posted over on LS1tech (which I thought I had posted here, too, but maybe not...) I posted some measurements showing how mine were offset. Another member posted that he had to use shims between the rotor and the hub to get the rotors to line up with the calipers properly.
 

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'05 CTS-V
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Copying from LS1tech:

I just swapped my summer wheels and tires back on, and while doing so did some fiddling around with the brakes. With my re-drilled OEM co-cast rotor installed, the rotor is pretty much centered (to the naked eye) in the caliper. With the "good" RB rotor installed, the rotor is clearly not centered - it's shifted towards the inside. Again, just eyeballing it, I would estimate the gap is about 2-2.5mm to the outside and 0.5-1.0mm to the inside. I should've dug my feeler gauges out of the garage to get some actual measurements, but I didn't think of that, and it was getting dark and I'm hungry. :) Maybe tomorrow I can re-attack.
So, it took a little longer than "tomorrow", but I did get back to this today. I went ahead and pulled the passenger side apart and got out the feeler gauges to get some measurements with the OEM and RB rotors. I measured from the rotor face to the machined surfaces where the black arrows are pointing, at the top and bottom of the caliper.



As I said before, neither rotor is new, but both of them have little to no wear (no perceptible lip on the face of the rotor).

OEM rotor - inside: 0.084", 0.090"; outside: 0.079", 0.075"
RB rotor - inside: 0.044", 0.050"; outside: 0.124", 0.108"
(in metric terms, that's 1.5 - 2mm off center)

Sho'nuff, the RB rotor isn't centered on the caliper as well as the OEM rotor is. Over on cadillacowners.com a guy said that he had experienced a similar failure on his Trans Am that had a Porsche "big red" big brake kit on it, and that it turned out the rotor was off center by "a few hundredths". Well, the RB rotor is off by a few hundredths on my car.

Edit: I'd be curious to know if anyone else with RB rotors (either 355mm or 370mm version, with V1 or V2 calipers) sees a similar offset. No feeler gauge measurement should be necessary - on my car I could easily see the difference with the naked eye.
 
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