Screeching noise source identified

[Steve D.]

Following suggestions from a recent post, I identified the source of the screeching noise during revving as the NEW fan clutch. Is there any way to quiet a screeching clutch?

Steve

[Loren L.]

Re: Screeching noise source identified

Yes, send it back to the seller and ask for PLan B - where he sends you another or your $$$ (and core?) back.

[Joe L.]

Re: Screeching noise source identified

Following suggestions from a recent post, I identified the source of the screeching noise during revving as the NEW fan clutch. Is there any way to quiet a screeching clutch?

Steve

Steve------


Is this a GM #3916141 Eaton-manufactured clutch?

[Steve D.]

Re: Screeching noise source identified

Joe

I'll check the PN when I get in this evening.

[Steve D.]

Re: Screeching noise source identified

Joe

The only identifying marks on the clutch are on the forward facing face and they are a) an arrow point in a clockwise direction and b) the numbers 27110050. I bought it from Corvette Central sometime back when I was assembling the engine.

[Joe L.]

Re: Screeching noise source identified

Joe

The only identifying marks on the clutch are on the forward facing face and they are a) an arrow point in a clockwise direction and b) the numbers 27110050. I bought it from Corvette Central sometime back when I was assembling the engine.

Steve------


Can you post photos of it?

[Steve D.]

Re: Screeching noise source identified

Joe

First attempt to attach a photo. It apears to have uploaded, so here goes.

[Joe L.]

Re: Screeching noise source identified

Joe

First attempt to attach a photo. It apears to have uploaded, so here goes.

Steve------

This is definitely not the GM #3916141, I don't even know if it's an Eaton-manufactured piece. It may be a Hayden, Four Seasons, or some other aftermarket brand. It could even be a Delco part but, if so, just an aftermarket-type piece in a Delco box. It is a thermostatically-controlled unit as opposed to a real "el cheapo" non-thermostatic type.

I'd say you got a defective piece, though. Quality is less certain with a part like this, but it should not screech. If you're sure the screech is caused by the clutch, I'd say return it.

[Michael W.]

Re: Screeching noise source identified

How did you differentiate the sound coming from the clutch vs. a loose/slipping belt?

[Steve D.]

Re: Screeching noise source identified

The noise stopped after I removed the fan and reinstalled the pulley and belt.

[Michael W.]

Re: Screeching noise source identified

The load from the fan might cause the belt to slip. Been there, done that. New fan belts are cheap and are good to keep as spares anyway.

[Steve D.]

Re: Screeching noise source identified

I thought about that, but the noise really sounds metallic. The belt is new, but I'll try another one to be sure.

[Tom L.]

Re: Screeching noise source identified

I went through a very similar problem with my '72 BB w/ a/c. Does your car have a captive belt and it it in place? I went through the same procedure you are going through and almost bought a new fan clutch but re-considered.

Turned out that my problem was that the captive belt was not installed, I didn't take it off but didn't do anything about it. Many told me it wasn't needed. Perhaps on non-a/c cars it may be the case but the big 7 blade fan used with a/c cars was too much of a load on the single belt on the water pump pulley. Once I realized that I HAD to put the captive belt on the problem went away. Good luck!!!

[Stuart F.]

Re: Screeching noise source identified

By captive belt, do you mean a separate belt running between the crank pulley and the water pump pulley which would use an idler pulley to provide adjustment? Otherwise, not sure what a "captive belt" is.

Stu Fox

[Joe L.]

Re: Screeching noise source identified

By captive belt, do you mean a separate belt running between the crank pulley and the water pump pulley which would use an idler pulley to provide adjustment? Otherwise, not sure what a "captive belt" is.

Stu Fox

Stu------


A captive belt is one that runs between the water pump and crank pullies with or without an idler pulley. As a matter of fact, in the truest sense, it's a belt that runs between these two pullies with NO idler for adjustment. MANY Corvettes from about 1966 onward used a captive belt.