Overrunning alternator (clutched) pulley on B4 with 1Z?

[MikeB4]

My '97 Passat TDI (B4 with 1Z) has a standard fixed alternator pulley. I will be replacing the alternator soon with a Bosch remanufactured one that is on the way. Is it possible, and is there advantage to putting on an overrunning alternator pulley on alternator that I'm ordering, even though it didn't come with one? My belt tensioner is good and replaced periodically, but it still vibrates a decent amount.

Thanks,
Michael

 

[ToddA1]

Yes and yes… this has been discussed many times.

-Todd

 

[Abacus]

It’s worth it, Gates 37010P.

 

[MarsBar]

Absolutely!!!

 

[Mozambiquer]

Yes, make sure to get the Ina ones that are made in Germany, not the aftermarket Chinese ones. If you need one, I've got a few.

 

[Windex]

The advantage is that the clutched pulley removes the rotating mass in the alternator from the load on the crank pulley. The AHU and 1Z pulleys have been know to deform the crank and sometimes (if bad enough) affect the timing / timing belt to the point of hard starts or even valve damage.

The clutched pulley provides some insurance by removing that amount of rotating mass/inertia from the belt system, and by virtue of driving the belt, the crank pulley.

If any of that makes sense... :-/