"you MUST not torque up using the belt method, you are putting the full force of the torque against the woodruff key on the pulley which is only a cast piece, you will sheer this and destroy your engine.... the workshop manual and how MJ does it is correct.
The factory way of holding the crank whether V8, V6 or inline 5 are the only way to do the belts..."

I understand what you are saying here but I don't think it is so streight forward." Putting the full force on the key" assumes thet the shoulder of the bolt is in contact with the end of the crank. This therefore would mean that any further turning force is trying to turn the crank and (as you say) if the pulley is held by the belt, risks the key shearing off.

If the shoulder of the bolt though is resting on the front face of pulley, is not the inverse true? whereby holding the pulley prevents the turning force from trying to turn the pulley as the bolt bites into the aluminium.

If the bolt bites into the aluminium pulley face whilst the crank is locked, could this not result in the same problem? The bolt will try to turn the pulley.

There is also the washer on the bolt to consider which should help prevent this.

I've also heard stories of the pulley key shearing even when using a crank pin.

I will use the pin in the future if that is what the book says and MJ recomends but I don't think that either way is bullet proof.

A couple of observations:

The pulley is steel.

The new bolt has a waxy substance between the bolt head and the washer. When its being torqued, the washer stops turning as it contacts the pulley and the waxy stuff squishes out as the bolt turns. I suspect this is by design to not put a rotational force on the pulley.

Only if it's one of her former patients.

I recently replaced front crank seal on d3 and I initially reused the bolts and torqued them without difficulty but when I went to do the 2 no 90° turns i only got about 60° on the ist turn and stopped as I was concerned that they would ring off ( seriously tight) I then ordered a set of new bolts which I torqued and did the 2 90° without concerned ,i had thought it was down to the originals being stressed ,i wonder now if they were waxed

You can see the little spots of wax in this pic. I never thought about it before this discussion - it was just something that happened. Its not there on the V6 bolt afaik, but thats a steel block so a bit stronger. Possibly its on the V8 one to mitigate the effect of the twisting torque on the alloy block? If I remember I will get a better look at the next new one.

http://forum.a8parts.co.uk/attachmen...1&d=1616793415

New thermostat, the correct way up :rolleyes:

http://forum.a8parts.co.uk/attachmen...1&d=1616793415

Timing gear back on

http://forum.a8parts.co.uk/attachmen...1&d=1616793415

I had the top water pipe powder coated with the sump since it was pretty scruffy

http://forum.a8parts.co.uk/attachmen...1&d=1616793415

With not wanting to degenerate this thread all I’ll add is that any manufacturer spends literally millions on developing a car and it’s workshop procedures....

Deviate from that at your peril on critical items as cam belt replacement

how many times have you seen specialists using tipex to mark cam locations only for the cam timing to be out as they’ve not used the correct cam locking tools???

I made no reference at all to camshaft timing and completely agree that short cuts with this procedure and not using the correct tools is simply asking for trouble.

As for manufacture spending millions on research and development, of course they do, and yet they still get it wrong sometimes.

I have already conceded that in the future I will use the crank pin to hold the crank. This is not because the manual says so but because it has been tried and tested by someone with much more experience of working on these cars then me (MJ).

That surely is the point of this forum. Not degenerative by any means. As long as we are polite than we all benefit from the exchange of ideas and learn from these exchanges.

A while back I mentioned to a good family friend that I was going to have the engine completely inspected after the accident damage work was repaired and he said it’s not worth it.

He said you had the timing belt, tensioners, crank pulley etc work done a few years back and that he wouldn’t waste the money. I told him to watch this space...:D

Now, I would consider the garage that did all of this work previously to be a reputable one, and yet I still see pictures that scare the excrement out of me. Crank pulley not seated correctly, thermostat not installed the right way round, timing not correct. Just these things alone is why I knew this would be worth while.

Thank you MJ. Your attention to detail and can-do approach to tasks is unparalleled +++:cool:

After the horrors of the murple, all this stuff is just minor niggles :rolleyes:

Freshly powdercoated sump:

http://forum.a8parts.co.uk/attachmen...1&d=1616880862

Good crank pulley on the left, less good one on the right. The crank sprocket is very hard high-carbon steel whereas the pulley is much softer so when it was rattling about the sprocket both wore away and displaced the steel of the pulley and ate in to it by a couple of mm. The material which was worn away is visible as rusty dust, but most of it was just smushed around in to the pattern of the sprocket.

http://forum.a8parts.co.uk/attachmen...1&d=1616880862

Good pulley mounted up.

http://forum.a8parts.co.uk/attachmen...1&d=1616880862

Replacement fan bearing

http://forum.a8parts.co.uk/attachmen...1&d=1616880862

The engine is back on the separating table, but the wrong way round

http://forum.a8parts.co.uk/attachmen...1&d=1616880862

so that I can replace the crank rear main seal as this was leaking quite badly. Audi won't sell you a seal - there isn't even a part number for it. Instead, you have to replace the entire rear plate (for £300) which also requires the upper sump to be removed :tuttut:

http://forum.a8parts.co.uk/attachmen...1&d=1616880862

Luckily Elring are having none of this silliness and will happily sell you the seal on its own for £25 or so. You just have to use the part number for the 2.5 TDI seal to find it :rolleyes:

http://forum.a8parts.co.uk/attachmen...1&d=1616880862

New seal in place

http://forum.a8parts.co.uk/attachmen...1&d=1616880862

Drive plate back on with new bolts

http://forum.a8parts.co.uk/attachmen...1&d=1616880862

Engine spun round and back on the gearbox. I can't attach the converter until the morning as the rear main seal has to sit for 4 hours before the crank can be turned, presumably to allow the material to relax in to position after fitting it.

http://forum.a8parts.co.uk/attachmen...1&d=1616880862

Pre-filling the gearbox through the oil cooler return. I put 1L in the converter and pump while the sump was off, and put another 8L in like this so the level should be pretty close when it starts up again.

http://forum.a8parts.co.uk/attachmen...1&d=1616880862

Mannol AG52 again, as the 5HP seems to respond really well to this stuff and its £4 a litre instead of £12 for OE! I have also used Mannol in the diffs (£6 a litre instead of £16) and in the engine too (same price but comes in a barrel instead of a stupid cardboard wine-box). It seems to be well made stuff at sensible prices so is going to be my default choice from now on +++

http://forum.a8parts.co.uk/attachmen...1&d=1616880862

Quite appropriate stamp on the crank pulleys.