Another centre lock failure?
Another centre lock failure?
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Discussion

LaurasOtherHalf

Original Poster:

21,429 posts

226 months

Sunday 24th June 2012
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Pure speculation, but just seen dale post this off B2G, & I do wonder about these things.....

http://www.youtube.com/watch?v=NbE6OzjyVV0&fea...

Looked painful

thegoose

8,077 posts

240 months

Sunday 24th June 2012
quotequote all
Ouch! The principle of centre-locks can't be to blame - look how many race cars use them - so I guess it must be an issue of whether they're correctly screwed on.

Seems odd though, usually if a wheel starts to get loose you can feel it get a bit wobbly, then slow down and check what the wobble is.

theredbaron

1,166 posts

235 months

Sunday 24th June 2012
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Makes you wonder if centre locks really have a place on a road car. Race cars are lifed time wise, with know other outside influences, look great though !

MadMark911

1,755 posts

179 months

Sunday 24th June 2012
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Was that a 4 litre? eek

LaurasOtherHalf

Original Poster:

21,429 posts

226 months

Sunday 24th June 2012
quotequote all
thegoose said:
Ouch! The principle of centre-locks can't be to blame - look how many race cars use them - so I guess it must be an issue of whether they're correctly screwed on.

Seems odd though, usually if a wheel starts to get loose you can feel it get a bit wobbly, then slow down and check what the wobble is.
Any car I've driven I change into fifth gear for pflanzgarten2, I don't know how many threads there are on those centre locks but at fifth gear I'm guessing you'd feel the wobble for a split second before it came loose.

Aren't the design of these different to racing centre locks?

Driver unhurt I heard by the way

LaurasOtherHalf

Original Poster:

21,429 posts

226 months

Sunday 24th June 2012
quotequote all
MadMark911 said:
Was that a 4 litre? eek
No 3.8

thegoose

8,077 posts

240 months

Sunday 24th June 2012
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LaurasOtherHalf said:
Any car I've driven I change into fifth gear for pflanzgarten2, I don't know how many threads there are on those centre locks but at fifth gear I'm guessing you'd feel the wobble for a split second before it came loose.

Aren't the design of these different to racing centre locks?

Driver unhurt I heard by the way
You've gone beyond the limits of my knowledge. I've never been to the 'ring and I don't know anything about the design of these wheels.

I did notice that it was the offside (based on a RHD car) rear though, which is odd as on that side the wheel's rotating inthe same direction as the thread does to tighten.

fioran0

2,410 posts

202 months

Sunday 24th June 2012
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The road cars aren't using the race car system though (either of the 2 versions Porsche use)
They have a unique consumer version that requires 11 pages of a manual to cover changing and refitting.

This is where the increasing levels of disquiet are coming from.
It seems like there's at least one report a month of failure and it's never pretty when it does.
Fortunately it's only been vehicles damaged so far.



993AL

1,939 posts

248 months

Sunday 24th June 2012
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I've been considering a 3RS GenII with centre locks. The seller said the car was in at an OPC as the lock nuts are on a re-call. I'm not sure how recent the re-call is.

fioran0

2,410 posts

202 months

Sunday 24th June 2012
quotequote all
Recall was pretty early on.
Porsche increased the torque spec and cars were taken in, checked for signs of wheel slip and new nuts fitted.
Hardware all remained the same, nuts just now no longer carried the torque value printed on them.
The first nuts stated the torque value on them which now was no longer correct.

LaurasOtherHalf

Original Poster:

21,429 posts

226 months

Sunday 24th June 2012
quotequote all
thegoose said:
You've gone beyond the limits of my knowledge.
Here's another gt3 taking a somewhat unorthodox line:
http://www.youtube.com/watch?v=E19Y46vnSD0&fea...

It's really a combination of 3 corners, handily called pflantzgarten 1&2 (?!), it's one of the best sequences on the track & one of the things that defines the circuit-remember those shots of CSL's flying from the 70's? That's pflantzgarten 2 (where the camera man is standing on the original vid).

The thing that makes me wonder about the hub failure is he crashes (by the look of it) on the "easy" bit-the uphill left hander before the drop off (or where the 996 gets back in the track after his spin). If it was the end of an accident on the first part I doubt he'd have made it as far as the second.

graemel

7,229 posts

247 months

Sunday 24th June 2012
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I must admit I don't like the idea of centre lock wheels on a road car. At least with the race cars you get a locking pin that will prevent the centre lock coming off completely.

FarQue

2,339 posts

228 months

Sunday 24th June 2012
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graemel said:
I must admit I don't like the idea of centre lock wheels on a road car. At least with the race cars you get a locking pin that will prevent the centre lock coming off completely.
This. I've wondered why they didn't bother with a locking pin. I suppose that a retro-fit solution would have to include new hub/spindle assemblies?

arcamalpha

1,117 posts

194 months

Sunday 24th June 2012
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FarQue said:
This. I've wondered why they didn't bother with a locking pin. I suppose that a retro-fit solution would have to include new hub/spindle assemblies?
They do have a locking system of sorts - a button thingy in the middle of the hub. This engages splines that stop the wheel coming off. I think one issue is that if the wheel is incorrectly fitted, the locking thingy may not be the correct (locked) position...

It wouldn't surprise me to find regulars at track days swap wheels themselves without a proper torque wrench.

FarQue

2,339 posts

228 months

Sunday 24th June 2012
quotequote all
arcamalpha said:
They do have a locking system of sorts - a button thingy in the middle of the hub. This engages splines that stop the wheel coming off. I think one issue is that if the wheel is incorrectly fitted, the locking thingy may not be the correct (locked) position...

It wouldn't surprise me to find regulars at track days swap wheels themselves without a proper torque wrench.
Ah, I bow to your knowledge Sir. Can I assume you're not supposed to do them up with yer average 'Halfords Professional' socket set?

fioran0

2,410 posts

202 months

Sunday 24th June 2012
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arcamalpha said:
It wouldn't surprise me to find regulars at track days swap wheels themselves without a proper torque wrench.
Why?



HoHoHo

15,399 posts

280 months

Sunday 24th June 2012
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fioran0 said:
arcamalpha said:
It wouldn't surprise me to find regulars at track days swap wheels themselves without a proper torque wrench.
Why?
Over confidence probably.

That is until the wheel falls off mid corner!

Mermaid

21,492 posts

201 months

Sunday 24th June 2012
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Form over function. Have to admit, I do like the look of them. wink

fioran0

2,410 posts

202 months

Sunday 24th June 2012
quotequote all
HoHoHo said:
Over confidence probably.

That is until the wheel falls off mid corner!
It's a 600Nm nut. Without a proper wrench and or torque multiplier you won't ever get it off never mind back on.

Every failure I've seen has involved the hub/spindle shearing right off with the nut still screwed in place.

Edited by fioran0 on Sunday 24th June 22:17

keep it lit

3,388 posts

197 months

Sunday 24th June 2012
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fioran0 said:
HoHoHo said:
Over confidence probably.

That is until the wheel falls off mid corner!
It's a 600Nm nut. Without a proper wrench and or torque multiplier you won't ever get it off never mind back on.
fact