SC Alternater replacement
 

Hi I recently bought a Valeo alternator for my SC from Pelican. It has gone in ok and is apparently connected up correctly. Before putting the fan belt in place, the fan spins freely, however after connecting the fan belt and tensioning it up, the fan blades scraping on the lower part of collar housing. When I disconnect the fan belt the fan spins freely again. Any idea what the problem is?

Does the fan house have cracks on one or more of the four legs?

How Many shims are you using and is it a Porsche Belt or Conti?

^^^^ Doug, the Magnesium fan housing is prone to degradation if not sealed....cracks and simply coming apart due to moisture.
Try putting a bit more slack in the belt.

the way the alt gets bolted up to the housing, with the studs going thru the plastic shroud and nuts tightening against it, isnt great. ive cutout all the shroud attachment points and left 2. that way the alt gets bolted up securely metal on metal. hopefully the housing is not cracked. i would pull it out, inspect the housing, if thats ok- tighten all the nuts around the alt but tighten the ones on the top half a bit more. the idea being that the extra torque on the top might influence the alt to tilt up just a tad providing a tiny bit of extra clearance from the bottom of the fan.

even thought the alt is a very tight fit into the housing, did you tighten the bolts that hold the alt in.
is the alt seated all trhe way in.

might be worth a check if you pull it to check for cracks.

losen up on the belt. does not need to be super tight

Make sure that the shroud itself is seated firmly/correctly. Any play in it will allow rubbing of the fan as tension is increased on the drive belt.