Another "crank sprocket" broken

[Error404]

Is the magical washer specific to the ABY pulley then, as the cranks are the same as the 3B or 7A and I've never seen one on them?

[Greg_S]

As JP said, renewing the bolt and the special washer is essential.

[Jamo]

Don't need to believe or don't that's the beauty of free will since Paul founded the forum and many have used his faq to change a cambelt the information this is good enough http://www.s2forum.com/forum/showpos...2&postcount=41

[UrS4boy]

Comes from an Audi technical bulletin

According to Paul N. "Audi issued a number of technical bulletins of the timing belt job - you can go for 200Nm plus 180 degrees."

Still, that is heresay.

Show me a copy of the technical bulletin and I will believe.

[Jamo]

http://www.s2forum.com/forum/showthread.php?t=26409

http://www.s2forum.com/forum/showthread.php?t=27190

Comes from an Audi technical bulletin

[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

[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]

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

[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

[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.

[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

[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!?

[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]

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!

[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?