Hi all,

I'm replacing the fan and alt belts on my '90 C4.

There were 4 shims between each pulley half on disassembly; the car came with only those 8. I figure if 4 each was right for a used belt I'll need a couple more for a fresh unstretched belt.

I'll order some new ones, and while they're not expensive, it all adds up. Can anyone comment on how many I should get?

One each?
Two each?
More?

 

I have three shims under each pulley. According to the PET diagram, each 964 is supposed to have a total of 6 shims.

With your new belts install, how is the belt tension? Too tight?

 

No install yet; waiting on a fan bearing and alternator rebuild.

I just don't want to get into a situation where a lack of pulley shims keeps the car off the road (yeah.... that'd suck)

 

The amount of shims between the pully halves control the tightness of the belt. Less shims in between results in a tighter belt, so a new belt would need more shims than a stretched belt. You store the extras in front of the pully.

 

Thanks, Lou.

Let me approach this another way- what's the largest number of shims anyone has needed?

 

Any update on this? My worn belts were running 3 shims on each pulley w/ an extra shim hanging out outside each pulley. I just put it back together w/ new belts and installed all 4 shims on each pulley. The still belts give a bit, but not much. Maybe 1/8" or 3/16". Should I source more shims? I don't want to toast these new belts, or even worse, the fan or alt bearing, because I'm running too much tension/not enough shims.

 

mine had six each just like PET shows, and ended up with 4/2 2 spares and 4 between each pully halves just like Porsche shows. As note the was a TSB on the Alt pully assembley IIRC one belt is incorrect if you go off the PET number.

 

Its 6 and 6 for a total of 12 and they are the fan shims are different than the alt shims.