Sobre el tornillo piñon del cigüeñal del AAZ

He visto esta polea:

https://www.ebay.es/itm/Audi-80-90-B3-1989-Alternator-belt-tensioner-068105243D-Diesel-ARA71780/303169347315?hash=item46964d1ef3:g:yOEAAOSwyy1c7Mbn&autorefresh=true

Tiene buena pinta, me fio mas de recambio usado que la polea nueva, que puede ser JP-Group…

Yo a vueltas con mi locura…

Que dicen que el problema, es que la gente no lo aprieta bien, que hay que hacer un util:

https://bbs.zuwharrie.com/content?topic=128661.20

Just a few notes for anyone doing this modification :

1.  Using two pins properly fitted into the nose of the AAZ is all but bullet proof from my experience … My AAZ daily driver has the two pins , and with over 300,000 kilometers since mod and still pushing 28psi of boost with ease , I can tell you it will hold … I am now on my third timing belt with change-outs at approx. 100,000 km's , but the nose has not been touched since modification …  Two pins , new bolt , and Loctite … Vrrroooom ……….  [thumbsup]

2. The D-notch is another option , and most machine shops will do it for an hours labour  … I see some on here talking about a press fit , not sure if that is actually needed nor is it so on the actual TDI crank nose .. I have only did one true TDI , and the pulley was not a press fit …I truly believe the minor  rotational movement  in the gear's  fitment  is nothing to worry about .  I would be more concerned that you get the correct torqued on the new bolt .  Test it too ,  run the bolt without gear into the crank , just to be sure the threads are clean and smooth. Then install and torque as recommended  ..

3.  The biggest issue here with these engines is the actual service … If the gear and bolt were not installed properly , and torqued as VW recommends , I think failure is inevitable  …  Hold the crank with a bar , or proper lockout tool , then torque … Do not try tightening without a proper tool holding the crank nose , you will not get it tight enough …    Just out of curiosity :  a friend of mine checked the torque on the crank gear bolt , after it was tightened to VW specs , if memory services me correct I believe it was above the 250ft/lbs  !! Then you wonder why they hard to loosen ?

4. Oh and just to note :  It is not only the AAZ which fail … I had a friend who lost the nose onto a AHU TDI too … It was damaged to the point of beyond repair  , since his speed was so great at the moment of failure …  After it flew off , the gear was never found either ! :o  I guess the main thing to remember is  :  » follow the recommended service , and also use only OEM or similar parts » ….

Ya tengo deberes para las vacaciones, pillar este tornillo original en la VW, hacer el util y desmontar toda la distribucion…

pero eso no quiere decir que tengas que apretarlo mas de 90nM y 1/4 de vuelta

yo creo que ademas de que algunos lo aprieten mal es que la mayoría no usa fijador de roscas apropiado … en cualquier caso si pones la polea amortiguada reduces mucho el riesgo de que se afloje

La mia es amortiguada al final, por las fotos se ve.

No, no, en mi caso es que no pude dar el 1/4 completo, se me vencia el motor a un lao, quedarian 15º, que fijador el Loctite 270 que dicen? Yo en mi caso use el que tenia a mano, una autentica mier… encima fijacion media.

Asi que creo que me voy a hacer el util ese, tornillo nuevo de la VW y fijador bueno.