Fan Blade

[Richard Pressley]

I ordered a GM fan blade for my '67, 327 directly from Chevrolet. On one of the blades there is some sort of large rivet attached out toward the end of only one of the blades. The NCRS reference manual doesn't say anything about it being there. Is supposed to be like this?

Also the fan clutch I received, which is supposed to be the correct GM #, has "bronze" studs. The NCRS reference says black oxide intergral studs. Should I change them?

Thanks

[Joe L.]

Re: Fan Blade

Richard------

The "rivet" is actually a balance weight. Automotive fan blade assemblies have to be very closely balanced to avoid vibration and noise, as well as short life for the water pump and fan clutch. So, as a final step of the manufacturing process, the fan blade is finish-balanced to a close spec. If necessary, weight is added in the amount and place required to achieve the balance specs. Not every blade assembly requires the balance weight, but if it does, it does. I think that this was just as true 35 years ago as today. So, I expect that there were some original fans that had the balance weight added, too. I don't know how common it was. But, I know that the reasons for balancing the fan blade were just as important and well-known then as today.

As far as the fan blade studs in your fan clutch, I was not aware that Eaton had started using plated studs instead of the black oxide of yore. However, such a change is probably well within the allowable specs of the part. Personally, I would NOT recommend attempting to replace these studs under any circumstances. I think that you'll likely destroy the clutch or, at a minimum, greatly reduce it's reliability. You DO NOT want one of these things to fail catastrophically in service. This nuance of originality is just not worth it.

[Peter L.]

Re: Fan Blade

Richard - Re: Fan Clutch Studs.

Is this a new Chevrolet fan clutch or an NOS one? The original '67 fan clutch studs were black but as Joe said if it's a new one basically what you get is what's available now not 35 plus years ago. BTW, what's the part number of the fan clutch being discussed here?
Pete