ZR change in PDs?

Hello.

For the timing belt replacement on some engines (at least on 4-cylinder engines), it is my understanding that the crankshaft pulley sprocket with the "catastrophic bolt" does not necessarily need to be loosened (it is sufficient to remove the vibration damper pulley from the sprocket).

Nevertheless, there have apparently been problems with loose timing chain sprockets shortly after a timing belt replacement by workshops .
- Apparently, the gears were unnecessarily disassembled and then incorrectly reassembled.

What is the procedure actually like when replacing the timing chain on PD engines ?
Can the crown wheel gear stay in place, or must it be removed?

ulf wrote:

During the timing belt replacement (at least on 4-cylinder engines), AFAIK, the crankshaft timing gear with the "catastrophic screw" does not necessarily need to be loosened (it is sufficient to remove the vibration damper pulley from the gear).

Hi Ulf,

That's correct, unless the 8.8 is still available. There are "lazy" workshops that, instead of using Allen screws, will remove the central screw and, at the end, might even put the same screw back in (the very same one), with the well-known (and likely) consequences.

Quote:

What is the procedure actually like when changing the timing chain on PD engines? Can the crown wheel gear stay in place, or does it need to be removed?

While I've never seen a PD (presumably referring to a specific component) from the inside, the Hazet tool (model 2588-1), as far as I can tell, is designed to be attached to the KW wheel -> so you only need to remove the Allen screws from the shock absorber and it's done. I would be interested to know if the same screw (12.9) used in the VP-TDI is installed in the PD engine, or if the design of the crankshaft-crankshaft-screw assembly has been improved.

Hi!
"Oh... an old topic! But I just looked at the pictures from my timing belt replacement again. And I noticed that the central bolt of the crankshaft pulley is only a 10.9 grade. Is that normal, or have there been any problems with that so far? How about the 4-cylinder TDIs? Is the 10.9 grade bolt also used there?" The VPs had switched to 12.9...

Sure, here is the translation of the text from German to English:

"Dirk"

It can be done without loosening the KW screw.

Regarding the screw's strength rating, I'm afraid I can't recall anymore (damn Alzheimer's).

So, a grade 12.9 bolt is actually very rarely used in dynamically loaded connections because the bolt is simply too hard and brittle. A grade 10.9 bolt is actually the optimal choice. When replacing the PD, the timing belt gear does not have to be loosened.

Hi!
Thank you for your responses! I was aware that, fortunately, they didn't need to be resolved. I was just surprised by the severity. But that has now been clarified. The only question that remains is whether there were already solved puzzles available on the PD platform (just out of curiosity...).

Sure, here is the translation of the text from German to English:

"Dirk"

Hello everyone,

Here's just a guess about the 'increased mortality rate' caused by loosening the KW screw:

With my AAZ engine back then (which still had the groove in the crankshaft stub), I actually replaced the crankshaft because of this problem. I replaced the screw (grade 8. with a grade 10.9 screw.

After everything was installed, I roughly adjusted the ignition timing with a feeler gauge and then went to a mechanic to have the ignition timing properly adjusted (using a micrometer gauge).

By turning the crankshaft with a key, the camshaft was then set to top dead center (TDC) and secured with a ruler. Then the OT (over-the-top) was checked and the EP (end-of-period) was set.

After the valve timing was checked, the skilled mechanic, having forgotten to use the straight edge on the crankshaft, forced the crankshaft stub with some effort.

At least, the force applied might have been enough to cause a fracture in the adhesive joint of the thread on the KW screw, because 25 kilometers later, I had the same problem: misaligned valve timing, ruined KW strut.

Unfortunately, I couldn't prove anything to the workshop, and the car was going to be sold anyway.

Perhaps my assumption is correct.

Sorry for any potential inconvenience. Off-topic.


Regards...

Please provide the text you would like me to translate from German to English. Kuhni!