Heat discoloration on hub--normal?

Lionel Hutz · 10-25-2009, 10:12 PM

I've never seen discoloration like this on any of my previous cars. Both sides are like this at the front.

oneintheory · 10-25-2009, 10:28 PM

mine are much worse than that.

Lionel Hutz · 10-25-2009, 10:31 PM

Quote:

Originally Posted by oneintheory

mine are much worse than that.

Any idea what causes it? I don't think anything inside the hub should be getting hot enough to discolor metal like that.

gyrfalcon · 10-25-2009, 10:33 PM

Mine are similar as well. I always thought it was just cause I was working the brakes pretty hard at AutoX.

SPEZNAS92 · 10-26-2009, 03:10 AM

could it be from the factory?

fun2drv · 10-26-2009, 04:07 AM

I only have 300 miles on my car and they already look just like that. I was installing the splash guards yesterday and noticed that when I took the wheel off.

Cuz5150 · 10-26-2009, 02:43 PM

Very normal, saw a 4 month old 5series with the same problem at the rear hubs/rotors......or stop dragging the parking brake

its normal, is just the type of wheels we have, show lots of rotor surface I guess.

mallards · 10-26-2009, 07:13 PM

that is normal --- it's from the manufacturing process

jeremyc74 · 10-26-2009, 07:50 PM

Quote:

Originally Posted by mallards

that is normal --- it's from the manufacturing process

Yep. Localized heat treat, probably using inductive hardening.

10-25-2009, 10:12 PM	#1
Lionel Hutz Lieutenant 229 Rep 509 Posts Drives: '24 X5 50e Join Date: Apr 2009 Location: SoCal iTrader: (0)	Heat discoloration on hub--normal? I've never seen discoloration like this on any of my previous cars. Both sides are like this at the front.
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10-25-2009, 10:28 PM	#2
oneintheory no longer a BMW owner 152 Rep 1,463 Posts Drives: 2011 Ford Edge Sport Join Date: Jan 2009 Location: Suffolk/Chesapeake, VA iTrader: (0)	mine are much worse than that.
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10-25-2009, 10:33 PM	#4
gyrfalcon Ninja 14 Rep 335 Posts Drives: 135i Join Date: Mar 2008 Location: Texas iTrader: (0)	Mine are similar as well. I always thought it was just cause I was working the brakes pretty hard at AutoX. __________________ SGM/Coral
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10-26-2009, 03:10 AM	#5
SPEZNAS92 First Lieutenant 11 Rep 305 Posts Drives: 2009 135i Join Date: Mar 2008 Location: Studio City iTrader: (2)	could it be from the factory?
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10-26-2009, 04:07 AM	#6
fun2drv Lieutenant 262 Rep 561 Posts Drives: '23 M5 Comp Join Date: Mar 2008 Location: Columbia, TN iTrader: (0) Garage List 2023 BMW M5 [10.00] 2023 BMW M5 [0.00]	I only have 300 miles on my car and they already look just like that. I was installing the splash guards yesterday and noticed that when I took the wheel off.
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10-26-2009, 02:43 PM	#7
Cuz5150 Major 215 Rep 1,489 Posts Drives: 06-M3ZHP/04-M3 Vert/02Duc998 Join Date: May 2008 Location: NJ iTrader: (0)	Very normal, saw a 4 month old 5series with the same problem at the rear hubs/rotors......or stop dragging the parking brake its normal, is just the type of wheels we have, show lots of rotor surface I guess. __________________ -Diplomacy is saying, "nice doggie while trying to find a rock"- 07-Z4 coupe-Black/Black/6MT/sport/premium/X 04-M3 vert-Black/Imolla/6MT/Cold/Xenon/HK/ 06-M3 Coupe-Mystic/Black/6MT/ZCP/Xenon/HK/ 09-135i- AW/Bk-Lette/6MT/M-pac/Nav/Hi-Fi/Usb-Ipod/SOLD
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10-26-2009, 07:13 PM	#8
mallards New Member 2 Rep 15 Posts Drives: 135i Join Date: Aug 2009 Location: US iTrader: (0)	that is normal --- it's from the manufacturing process
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