Ed Hughes

Gates should be fine, in quality. But it comes down to total/proper length.

rusnak

Yes, "washer" is the wrong word. I was eh....texting while at a stoplight (should not do). The fan bottoms out on a shoulder on the alternator shaft. The spacers between the pulley halves prevent the pulley from pinching the belt and "should" make the fan solid against the shaft shoulder.

But with wear, the fan can clunk around on the shaft, especially with a belt that does not fit the pulley well. I think it's more an issue with the belt bevel angle, or something. I noticed that some belts simply don't fit as well.

It's really important, it should be noted, not to overtighten the belt. Doing so will put too much stress on the alternator bushings and cause them to fail. The noise noted in the video sounds a lot like a fan clunking around on the alt shaft. I suspect poor fan fitment, poor fan nut mounting, or an issue with the belt causing the fan to wobble around.

Bkresse

Tried the Gates belt. No joy. Same noise... But now I have a backup belt.

I think I'm going to go ahead and rig the alt shaft to spin it using a drill, I want to spin it with and without the fan. I'm leaning towards the alt being defective; however, I want to have some definitive evidence that it is indeed the alt before I ask the shop to replace it again.

Thanks for your help guys, I'll let you know how it goes.

Ed Hughes

Have you tried moving the shims to adjust one of the new belts looser? That would put less load on the shaft, and maybe get you something different.

Bkresse

Ed, funny you ask... about the shims.

Through this whole mess I ended up with three different belts that required three different shim allocation combinations.

Goodyear Belt (Porsche Dealership) shortest belt- 6 shims behind and 0 in front
Contitech/Contenental Belt - 3 shims behind and 3 shims in front
Gates Belt longest belt- 1 shim behind and 5 in front

Each configuration resulted in no detectable change in the noise intensity or frequency.

In all cases I was looking for a slightly loose fit. I measured between .25 and .5 inch cheating to .5 when possible. Each fit was different, but all fit within this tolerance.

Bkresse

Latest video, same noise with Gates belt.

theiceman

Wow i know it probably isnt as I have read that whole thread and been keeping up but based on that vid alone I would have said that sounds like rod nock .
But has anyone considered that the strain you are putting on the alternator also reflects some strain put on the crank pulley ? how do we know the noise isn't coming fom down there ... Not likely I agree but all possibilities are worth discussing no ?

Bkresse

theiceman, I really hadn't thought about that strain point yet. I think it's worth another look and exploration with the scope.