Curing belt chirp -- Looking for a sure-fire remedy.

Started by av8, March 25, 2005, 10:05:58 PM

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av8

I have a chirp from the belt connecting the crank pulley to the fan on my F-1, and it's not responding very well to the usual remedy, i. e. belt dressing. It's a new belt (less than 1K), correctly adjusted, pulleys correctly aligned, and it responds to a generous squirt of belt dressing for about 20-30 miles and then it's back to chirping. (Sounds like the noise the giant, mutated ants made in the '50s Sci-Fi movie "THEM!")

I'm thinking it's probably time to remove the belts, clean and maybe scuff 'em with 80-grit, and clean the pulleys. Not sure if that's the cure; I've always gotten rid of belt chirp by replacing the offending, usually well-worn belt, but that hardly seems smart with new bellts.

Ideas?

enjenjo

Might I suggest the problem may not be the belt, but one of the pulleys? I had that problem on a Ford one time. the pulley was worn enough that the belt wouldn't make good contact, and no amount of dressing would cure it. Replaced the water pump pulley, and the problem was gone.
Welcome to hell. Here's your accordion.

av8

Interesting. It's worth a try, Frank. Need to locate some good pulleys first. Thanks for the direction.

Mike

zzebby

I've had the same problem with a BBC ...........but couldn't get new pulleys.  Try sanding the grooves to take off the shine and also you might try a better grade belt.  A lot of the belts on the market,  even the supposedly good grades will make noises.  Some of them are on the minimum width even when new.  Manufacturor saves a few pennies by cutting them to the min width and thickness.

C9

I had the crank and water pump pulleys powder coated black on the Buick engine in my roadster.
Mainly for appearance, but it added to the friction capabilities of the pulley.
Which it sorely needed since there wasn't much V-belt "wrap" around the water pump pulley (w/mechanical fan).
Single belt setup as well.
(Lack of sufficient wrap on your engine may be contributing to V-belt squeal on your flat motor although I'm not sure what you could do there.  Other than an idler on the back side of the offending belt so as to give more wrap.)

The powder coating in the groove lasted about 30,000 miles and now that it's worn off the belt slips worse than it did previously.
The previous slippage - w/powder coating - wasn't much which was surprising considering how little the single V-belt wrapped around the pulley and it only happened when the throttle was quickly depressed.

The reverse would probably be true for you.
Powder coating your pulleys would probably stop the slippage and if not, you'd have an appearance gain.

I wonder as well if it would help to use the 1950 on up passenger car narrow V-belts and pulleys.  My friends 49 coupe with wide V-belts and very close to stock not-tuned-as-well-as-it-could-have-been engine slipped the V-belts a lot more than my 50 coupe with slightly stronger and in better tune engine with the narrow belts.

The powder guy did a lot of Harley stuff and powder coated a lot of chain sprockets.
He told me that it was surprising how long the powder would last considering the metal to metal contact between chain and sprocket.

Just to give you an idea of how little V-belt wrap was around the water pump pulley, here's a pic of the double V-belt setup that's going in the 31 which is also 462" Buick powered.  It has the same amount of wrap the 32 does.
(I'd do the double V-belt bit on the 32, but there just isn't any room.)
I think this will do it as far as V-belt squeal is concerned.
C9

Sailing the turquoise canyons of the Arizona desert.

Mr Cool

have you tried that stuff you use to stop the squealing on brakes?
It soaks into the belt and stops it slipping and squealing for ages, and if it does start making noise again, just spray on some more.
And it DOES work on V belts too, Im not kidding.
I first came across this one when a bobcat operator was digging out my driveway many years ago, he said he has to spray it on about once a month.
Im nobody, right?
And dont forget, nobody\'s perfect.

Crosley.In.AZ

I have replaced pulleys for this noise.

Also I used some very coarse sand paper to scuff the snot out of the  area where the belt rides .  This stopped the noise too
Tony

 Plutophobia (Fear of money)

Nick32Vic

If belt dressing helps it for a little bit, get a bottle of baby powder and put a couple puffs on each side of the belt. It should stop it for a while. My dads car had the same problem. we did everything to fix it. Belt dressing only worked for about 10 minutes. Nothing worked but then Someone told us about the baby powder thing and it fixed it. Well, we have to put it on about 4 or 5 times a summer but its better than 4 or 5 times every little trip we take. Give it a try.

Nick

Mikej

I had this problem also. Tried NAPA, Carquest , O'Rielly and Gates belts. All crap. Seems like they all ran in the bottom of the pulley. My best guess is that they are metric. I went to a cogged belt. Not as deep. I can get the brand name if you would like. No more slipping and the alt. works better.

40_Tudor

I had the same problem with my 78 Bronco 351m. New Gates belts made noise. I finally got a FoMoCo belt from Ford and that cured it. Not sure if it was the belt angle or material.
40_Tudor

jeffa

Quickest way to test if the belt is too narrow: the bottom of the pulley groove will be shiney. The belt should never ride in the bottom of the groove.

av8

Thanks for all the good suggestions/direction.  I will "deglaze" the belt and the pullies this week as a first step, and start looking for some new pulleys just in case.

FWIW, I gave the belt a shot of WD-40 Friday evening as a temporary fix and haven't heard a peep -- or chirp -- from it since! It'll be back until it's cured by elmiminating the problem, however. Again thanks to all, and I'll post a follow-up once things are set right.

Mike

reborn55

Sometimes taking the belt off and reversing the direction of the belt will cure the problem

Rochie

Mike,
here's an old flat rate mechanics trick to get rid of chirps and squeals coming from belts.  Use a fairly corse rat tail file, in as clear a spot as you can find, and hold it up against both sides of the belt with the engine at idle.  It will take a bit off the belt but it really improves the grip between the belt and the pulley.  BE careful of the fan and pulleys though, wouldn't want that file taking off anywhere.
Rochie

grazza

WD40 will, sometimes, degrade the belt.  Try rubbing a generous layer of hand bar soap [wet] on the belt, usually works and is usually a permanent fix.
Graeme
My Mind Is A Dangerous Place
I Should not be allowed to wander through there alone