P-track

Just did the belt change on my C2. Cranked the enigne first to check all belts are seated and tight. Then started the engine, all looked well but after 20 seconds the alternator belt starts smoking at the pulley. Turned off the engine and grabbed the fire extinguisher, luckily no fire or damage...

Part number for the alternator belt was 999 192 343 50 and I replaced it with the same partnumber Porsche belt. I used the same amount of shims on both pulleys. Tension on both belts feels just like with the old belts.

Any thoughts about what I did wrong, could just be the pulley isn't holding the belt tight enough causing it to slip?

Help appreciated!

This was the pulley layout:

bobt993

You installed the small washer (bushing in the middle) backwards so it locked the alternator to the fan speed. That will cause the belt to slip since it is trying to spin faster (pulley raios are different). When you put it all back together make sure the two pulley spin separately before putting the belts on.

P-track

You mean the smaller diameter of the washer should face forward?

bobt993

As you assemble things back make sure the bushing ( which has a smaller diameter and a larger diameter on the other side) allows the alternator shaft to spin free of the fan. I have seen this happen where the two shafts are locked together which causes the one to try and spin faster thus burning the belt.

P-track

Great thanks, will give that a try ( pretty sure that I had the washer the wrong way around ).

pp000830

I wonder of the assembly error described above caused the replacement pulley Porsche Technical Bulletin on the subject?

kjr914

Looks like you have the rear-most washer flipped as well, if your pic is exactly as removed (good idea BTW). The fatter part of the rear/alternator pulley spacer/washer goes directly against the pulley halves, so the skinnier part points away from the rear/alt belt.


hmmm, I had kinda wondered that myself and this seems to be a really good engineering (/German/Porsche) reasoning for the updated pulley.

e9stibi

It always good to have the factory manual!

axl911

I accidentally did this, and it indeed locked the alternator to the fan.

Anyway....you know what? This is how you can do a low budget RS hub conversion!!!

Just install the middle backward and not put on the outer belt!!!

No RS part needed!!!

TRINITONY

however this time around, my alternator pulley is locking up, belt smoking, pulley hot, regardless of which direction I put that small washer. No problems with just the fan belt mounted. If I add the alt' pulley without the belt, regardless of the direction of the washer, ait' will turn independently of the fan. Once I add the alt belt, not tight, using about 5 washers, it starts smoking.........................................

I have to check to see if my alternator light is coming on with just the fan belt on.

RS conversion maybe.