cam belt position is looking odd

[S2_avant 19930325]

20220404_073915.jpg Of course . if there is now washer in the front , mine is 4 mm , then the complete front hub to all the belts will come 4mm closer to engine , i mean it cant travel out. Will check this. This is the washer that was in in there.


20220404_073845.jpgSo the underside of the bolt goes directly to that surface at the bottom , no washer ? The i must pu a bit of oil under the bolt head to when i tourque it.


2022-04-04_074455.jpg Why is there no 5th hole for the "pin" on the hub pulley ? There is one on the belt holder pulley. I start thinking if they have put some other kind of belt pulley on the crank ??

[Tractor Dave]

That looks like the diamond washer to me.
You should have a little locating bump on your sprocket. The diamond washer fits in the groove inside the bottom sprocket then the damper on top.
Here is a pic of old bottom pulley next to new one from Chef here.
You can see the old diamond washer in the old sprocket.





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[Tractor Dave]

Diamond washer is 034105193

If that was my car I would be replacing all the non original parts for stuff I trusted. New top pulleys are available at Audi Tradition and not too expensive. You must support the pulley when 're torque the bolt. Get a new bolt while you are there.

[S2_avant 19930325]

Great . the belt is moving out now , about 3mm on the lower pulley. So you recommend a new pulley on the camshaft ?

[Tractor Dave]

I would. Just checked and they are 67 euro. 034109105

[K Simmonds]

Looking closely at the OP's pic's it looks like he already got a billet bottom pully in place, of the type with a separate keyway and the teeth aren't as nicely cut as on Chef's one's. This could be the cause of the belt running too far forward.

It would be good to able able to try at least try a stock pully on the camshaft to rule out that causing problems, however I don't know how that's going to effect the performance of the cam's, I would imagine someone fitted that adjustable for a reason as their not cheap.

It can be a real pain putting things right when you don't know what works been done and what parts have been used.

[S2_avant 19930325]

The bottom pully when i touch it , the surface is not smooth. At some places you can feel small groves. I will not touch the cam sprocket yet. Will first change the bottom one.

[S2_avant 19930325]

When you look at my lower pully , the groves are almost like half of a circle , you can zoom in .Does not look like the upper pulley in the groves.

[K Simmonds]

I'm 100% sure that bottom pulley isn't OE, have now had a good look at your photo's on my lap-top, as you say the grooves or teeth are not cut in quite the correct pattern.

This is a very old type of billet bottom pulley which I have seen before but not for a long, long time.

Good plan to change that for one of Chef's before swapping any other parts.

[Tom_]

Which engines using that diamond washer? I cant find any info related to this part in ETKa. Currently I am assembling the engine (but stroker one) and have crank pulley from Terry. I only found some FEBI part (31815) and its an diamond washer, but very thin (0,14mm). Can someone explain it more to me?
Thanks

edit: It looks that this diamond washer is only for an AAN crankshaft damper as there are two types (older version without washer and newer version with washer) 7A/NM/NG/3B doesn't need to have this washer

[K Simmonds]

As far as I know it's only ABY/ADU engines which have this magic diamond coated washer, I've done several 3B belts as well as 10V belts and am certain they don't use one, not sure about AAN's as I've never worked on one. It's been eight years (and a lot of Vodka) since I did the belt on an ABY so my memory is struggling a little, am yet to do the one on my RS2 as it had a new belt not long before I got it.

If it's diamond coated one has to imagine it's there to introduce more friction between the nose of the crank and the harmonic damper as well as act as a spacer, though this is just a theory so I could well be wrong.

I also have one of the 0.14mm ones thick you describe left over from a cambelt kit I got for a T4 Transporter (same basic block), however when I changed the belt on that van it didn't have one fitted when I took it apart so I didn't use it upon reassembly and all was well. I simply put it in my new spares draw as I thought it could be handy someday.

Dave, can you recall how thick the diamond washer was when you replaced it doing yours mate?

I'm sure someone on here would be able to provide us with a proper explanation.

[Tractor Dave]

I have a used one. I will measure

[Tractor Dave]

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[K Simmonds]

Thanks Dave, that's completely different to the one I got in a T4 kit, which I've just measured at 0.15mm.

Now I've really had time to think about it I used a new one of those in conjunction with a new OE bottom pulley and bolt (parts provided by the owner) when I did the last ABY that I've worked on so I don't think I've ever had to purchase one of those washers... Yet.

If it's 3.3mm thick then it obviously acts as a spacer as well perhaps help provide friction between the nose of the crank and harmonic damper.

[newsh]

20220404_073915.jpg Of course . if there is now washer in the front , mine is 4 mm , then the complete front hub to all the belts will come 4mm closer to engine , i mean it cant travel out. Will check this. This is the washer that was in in there.


20220404_073845.jpgSo the underside of the bolt goes directly to that surface at the bottom , no washer ? The i must pu a bit of oil under the bolt head to when i tourque it.


2022-04-04_074455.jpg Why is there no 5th hole for the "pin" on the hub pulley ? There is one on the belt holder pulley. I start thinking if they have put some other kind of belt pulley on the crank ??

I think you already have some kind of billet steel sprocket, let’s see a close up, a stock sprocket has the lip cast in, the billet one has a steel ring pressed on.