Another "crank sprocket" broken

[Cobra]

Almost going quits on my S2 Avant.
Bought a AAN engine to rebuild, since my ABY had a hole on the block.
Everything went ok on the rebuild, at least it seemed like that.

Since the engine is in its place, I've had two crank sprockets broken, the litle piece that fits on the round part of the crank just disappears!!!
2 crank sprockets for just 2000kms!

What could be causing this?

The engine part around the sprocket is 054 115 109B
And the pulley that is attached directly to the sprocket 054 105 255E

Any compatibility issues?
Is there any upgrade from the OEM part?

[Jamo]

Yes buy uprated one volcano rs sells them so do other people
Did you use an impact gun to do up the crank bolt?

[Cobra]

Thanks for your answer Jamo.

I'm not sure, since the job was done on the shop, when I wasn't present.
Regarding the crank sprocket upgrade, do you know any brands that sell it?
Are there any differences between AAN and ABY?

[Jamo]

Pm volcano rs on the forum

[driftin jo]

They are not torquing the bolt up correctly, it is the only reason they brake.

[AndyP]

Thanks for your answer Jamo.

I'm not sure, since the job was done on the shop, when I wasn't present.
Regarding the crank sprocket upgrade, do you know any brands that sell it?
Are there any differences between AAN and ABY?

what have the shop had to say about this?

Are they using the correct locking tool and torqueing to the correct spec?

[Cobra]

what have the shop had to say about this?

Are they using the correct locking tool and torqueing to the correct spec?

They assume the damage if theres any to the valves.
I questioned them about the torque they used to bolt it in place, no one could give me an answer...

And now that you mention a locking tool and torqueing correctly I can see where the problem is...
Because my S2 is only homefried...
It shouldn't go through these sprockets like me eating chips!

[UrS4boy]

Timing belt and crank pulley info

What could be causing this? The engine part around the sprocket is 054 115 109B. And the pulley that is attached directly to the sprocket 054 105 255E. Any compatibility issues? Is there any upgrade from the OEM part?

Well the first thing that is wrong is the 054105255E is not the correct PN. The correct ABY (and AAN and ADU) PN is 034105255A (Item 5 in the diagram below). The other potential issue is the serial number of the AAN you are using. Later AANs used a different crank damper (Item 3) below than early ones. The later dampers need a special washer (see the second diagram). The main cause of broken crank pulley "keys" (actually cast as part of the pulley) is monkey lads using an impact wrench to remove and install the pulley (See the photo) instead of the proper crank lock and crank bolt tools and 19 mm (3/4") drive torque wrenches.

More crank pulley and Timing belt info here:

http://forums.quattroworld.com/s4s6/msgs/23002.phtml

[Cobra]

Any shop selling the locking tool?
Or does Audi sell it?

Does anyone has the correct Nm values for doing it the right way!?

[AndyP]

http://www.samstagsales.com/vwaudi.htm#crankshaft

The bolt should be torqued to 200Nm + 180° from memory, there is a guide on S2central.com

http://s2central.net/temp/timingbelt.html

[JP]

Incorrect torque values, using an impact driver, using loctite, not renewing the diamond coated washer when there is one and not fitting a fresh pulley and bolt will all lead to failures. Never had one break on me other than the very first one I pulled of my own car as I saw the last timing belt was done by a tire fitting place so I knew that it had had an impact driver on it and not replaced. Sure enough on removal half the keyway was missing.

[UrS4boy]

[url]The bolt should be torqued to 200Nm + 180° from memory, there is a guide on S2central.com http://s2central.net/temp/timingbelt.html

Your memory is potentially dangerous. Look at the S2central info. 350 Nm with the extension tool and 450 Nmn without it.

Here is a good timing belt procedure (written for an C4 UrS4/S6 with AAN but adaptable to ABY, ADU, etc):

http://12v.org/urs/FredMsTimingBeltR&RDIY.pdf

[Jamo]

I think His memory is right as that's what the Bentley manual quote if you haven't got the tool

[UrS4boy]

I think His memory is right as that's what the Bentley manual quote if you haven't got the tool

I found this diagram (below). No mention of what to do when you don't have correct tool (which BTW would be a torque wrench capable of more than 450 Nm).

[Jamo]

It's definately what Andy says S2central confirms

http://www.s2forum.com/forum/showthread.php?t=3331

http://www.s2forum.com/forum/showthread.php?t=33756