Alternator belt squeal

[aj81spider]

I don't know the answer to your question - but that impresses me as a lot of work (especially the crankcase pulley). It occurs to me that a bigger pulley on the 95 amp alternator might help (be all that's needed?), as that would provide more surface area for the belt to grip. My current theory is that the slippage is on the alternator pulley, which is pretty small and nice shiny brass.

However, it's funny that this chain reactivated. This week I'm working on my problem. No deep insight, but a little additional information.

I'm currently using a Delco 15335 belt, which is allegedly a high capacity belt and which squeals on startup, but generally once it stops squealing is quiet. The belt has definitely developed a little glazing on the side from slipping, and the squeal is loud and obnoxious on startup.

I bought the Gates 7417 mentioned above (without doing my due diligence). The 15335 is a 33.6 inch belt. The 7417 is a 42 inch belt. It would only fit my car if the engine grew substantially. The 7417 is advertised as a high capacity belt, as is the Delco and their cross-sections are very similar. They also look like similar construction. I'm guessing even if the 7417 fit it wouldn't fix the problem.

No magic answers - but you're not alone in this.

[spider2081]

bigger pulley on the 95 amp alternator might help

I am thinking the same thing but for an additional reason. Many alternators need to be spinning at around 1000 rpm to produce an output. One of the marketing points about the 95 amp alternator is that the headlights are brighter at idle and that the alternator puts out 14.5 volts at engine idle. This make me think the alternator is spinning too fast on engine start up and its output at that moment is great trying to replace the energy into the battery that was required for starting the car. Slowing the alternator's shaft speed down at idle might reduce its output and physical load on the belt. Combine that with more linear belt contact as mentioned and the squeal might be eliminated.

[DieselSpider]

I don't know the answer to your question - but that impresses me as a lot of work (especially the crankcase pulley).
I bought the Gates 7417 mentioned above (without doing my due diligence). The 15335 is a 33.6 inch belt. The 7417 is a 42 inch belt. It would only fit my car if the engine grew substantially. The 7417 is advertised as a high capacity belt, as is the Delco and their cross-sections are very similar. They also look like similar construction. I'm guessing even if the 7417 fit it wouldn't fix the problem.

No magic answers - but you're not alone in this.

Sorry about that. Since I do not have the original engine nor that particular alternator I only provided a link to depict the type of belt.

I have added a note to make that more explicit now to insure others do not get misled.

[TX82FIAT]

So, I've had the 95 amp alternator for at least eight years. My belt squeals at cold start up for about 3 seconds as well. However, it only does it on cold start leading me to think there is some merit to the alternator bringing the battery and system up to what it thinks it should be. If I'm driving the car for more than 10 minutes ans shut her down, a start up within the next two hours or so will have no squeals at all. Also, for some reason, maybe fuel pump and cranking draw. The car is "significantly" less likely to have cold belt squeal if I move the ignition key to the on but not start number 2 position for about 3 seconds prior to cranking for start. When the battery does not have to work hard to start less or no squeal. In addition to the above, there is a difference in ambient temperature. You are significantly more likely to squeal when starting in the cold.

Cold car that has sat for a couple weeks in cold garage will equal some noise..