Interesting Rotor/Hub problem!..

[Stix Zadinia]

I know it's a crap picture (from a mobile), but checkout the picture attached...

what the hell would cause this?, issues with casting or something?.

It's an ATE/Bilstein Rotor from the back of a W114 Mercedes, which was replaced just over 12 months ago (along with the fliexible hoses, and pads). The entire of the internal handbrake was removed from the hub at the same time so nothing would've been flying around inside which is the only thing i could think of.

It has to be the weirdest thing i've ever seen. i'm taking it back to the place i bought it to see what they think. just gotta get the thing off first.

PS. there isn't meant to be a hole there.....

[Nero]

casting fault/overheating...leave the handbrake on?

[Stix Zadinia]

theres no handbrake internals to leave on....

and they don't normally get _that_ hot. maybe if it was the front. but the backs should've been alright i would've thought.

casting fault seems to be the common answer, but i wouldn't expect this sorta crap from german made rotors.

[GTSBoy]

Very hard to tell from the photo, but if it isn't a casting fault, or other damage that has been caused to the iron during it's life, I would say that it has been hit by something.

cheers

[Stix Zadinia]

that's another thing that's got me puzzled. it's meant to be a surface for the hand brake shoes internally, and it's not thin. if something went through, it had to be with alot of force, and theres nothing around it damaged.....

cheers for the comments though guys, i don't wanna sound like i'm playing down everything!. i guess i'll wait to hear from the place i bought it tommorrow

[dbasteve]

I know a little bit about casting and Grey Iron......

It doesn't fracture like that. If the edges of the hole look polished it is most likely a piece of cold metal. If there is a hesitation in the pouring process the metal in the cavity starts to solidify and the remainder of the metal does not knit together forming what looks like a plug. Add a little heat and a bit of load and out it pops. It's not common for this to happen in modern foundries like ATE or to make it through the system but it's possible.

The picture is not brilliant but the rounded shape of the hole supports the theory.

[mondo2000]

but i wouldn't expect this sorta crap from german made rotors.

Just a side point...

I laugh when people talk about "German Engineering".

IMHO there is "Good Engineering" and "Cheap Engineering" and both can be done in just about any country in the world!

But yeah, dbasteve knows what he's talking about and this case is probably just a one-off freak thing.

[hotgemini]

But no other country on earth holds engineering with the same high regard as germany... I spent 20 minutes trying to work out where I was messing up my translation when I asked a german friend I was staying with what he wanted to be when he was older... I just assumed the dictionary was wrong when I worked out his answer to be "a famous engineer" I mean in australia that is an oxymoron.

[dbasteve]

While we're sharing stories.

I worked for a 100% German owned company in Australia many years ago (Mid 80's) and they are the most dedicated Engineers around. BUTT they are human just like the rest of us.
I'm not sure how many million rotors ATE are pumping out these days but it's not hard to beleive a few hundred get through the system each year. Which equates to a minute fraction of a percent in production terms.
The only way to pick up a problem like this is X ray which isn't ecconomical in high volume production.