TedH

My fan belt to is 'screaming' when I hit the go pedal. It sounds like the alternator/water pump belt for sure. I also have the Power steering pump belt. I removed the A/C belt and Air Pump/belt. There is no visible issue with belt/pulley alignment.

Is this a symptom of a dry-rotted belt? Stock AC Delco # is 17560 for fan/alternator. Local Advance Auto has a Car Quest # 15400. For $12, I can replace once it arrives this afternoon.

Not finding the P/N for the power steering belt. Since I have to remove it, would like to replace while I'm at it. Who sells the P/S pump belt? Advance doesn't even list one for it.

I am finding a few P/N's for the power steering belt:
GM 9433622
Dayco 15360

Carquest Dayco for fan/alternator: 15535 - w/out 70amp (assuming 100amp), 15540 w/70amp. Store lists just 15525 no matter what.

Funny, the lady I first spoke to gave me an incorrect # 15400. It does not fit the car based on the website. She said she would place order for 2pm today. I called them back and she didn't remember it... we had spoken just 15 minutes prior. I told the guy she must have amnesia...

They have the Carquest Dayco P/N 15535 in stock for $16. I am heading there now. P/S belt I had to order (15360). I am learning I have to check/verify as these folks just read it from the screen and usually get the P/N wrong. Sad, sad times

vince vette 2

Try Rock Auto - here's a link to a gates belt listed for it. They have other options. Should verify based on length.

resdoggie

Do you have normal or deep groove pullies that came on some L-82's? Mine began to squeak at 3000+ rpm. I have the deep pullies but the belts were for L-48's with narrow pullies. The ones I have now are 1/2" wide and fit properly. Also, make sure the belts are tight enough.

Big2Bird

What year? Did I miss that part?

71 Green 454

1980 L48, according to his profile page. I wonder if he checked NAPA for belts, they're made my Gates.
I just purchased 6 Gates belts from Rockauto for $7.96, just over $1 apiece.

Rescue Rogers

First I would check to see if its cracked, if not tighten the belt. If you need to replace it, bring it into Napa, Autozone or your favorite store, they should have a measuring tool or be able to cross reference the numbers

croaker

Sometimes removing A/C belt causes the squealing. No tension on that side if that makes sense

carriljc

Buy a quality brand name belt. I didn't believe it until the guy at Napa told me. So I went ahead and tried it since all else had failed to stop the squealing. I was surprised, but it did immediately stop the noise.

You can use some "Belt Dressing" from your local parts store if you are not certain which of your belts is causing the screeching. Spray it on 1 belt at a time and the one that stops screeching will the be the one that needs attention.

TedH

Measured the old belt at 54" outside circumference. That equated to the 15535 P/N for Dayco clogged belt. When I tried to install the new belt, the internal diameter was a problem; it won't clear without removing valve cover. As the power brake line and EGR hoses are a drag to remove, I checked next couple sizes and the 15550 adds 1.5" to the OD. I think this is the belt to use. The valve covers are stock height BUT the DART heads have a raised valve cover rail so I probably lost the room to use the stock belt. Not sure how I got that belt on last time unless I removed the valve cover back then. Will see if the 15550 does the trick.

TedH

Just trashed the 15550 belt... thought it was on crank pulley and stripped the inner surface. Need glasses.

Big2Bird

IF 80 is the same as 81, I can send you good numbers. It took years to wade thru the chaffe and find proper fitment.

Bikespace

I had to remove the oversized valve cover the PO had put on to get the alternator belt of my stock 79 L48. I swapped out for the correct valve covers.

TedH

I am up-sizing to a Gates belt from local O'Reilly's. Going to pick it up this evening. It is longer than the 15550 Dayco that i trashed this afternoon. I will be creating a 'folder' in my library (hard copy) so I have this info for either me or the next caretaker of my '80. It is an L48 in name only (L48 block, rods and crank).

mrvette

Biggest reason I went to serp drive is the belts have changed shape and width with the intro of metric parts on cars....the pitch on the V groove is narrower on old American cars....so the narrower belt rides on the upper/wider surfaces of the V.....and the back is not as wide, so sets lower in the pulley, and the backside of the belt has a U shape to it.....

need spec an old standard belt, tough to find years ago, I can only imagine today.....

all they do is get you a belt of same length not good enough , need same pitch to the V and width across the top also.....

theandies

Some v-belts have the wrong angle of "V" meaning the belt's "V" is not the same the the pulley's "V". This will cause lack of surface area the belt has in the pulley and cause squealing. Just something to look at when you do get your new belts.

TedH

Will advise once I install the Gates 7560 belt on Thurs (on order from O'Reilly's).

theandies

I just remembered I keep a spare alternator belt in my rear compartment. Its a Dayco 15545. This is for a 350 with no AC or power steering.

TedH

Thanks for your replies. I have replaced the fan/alternator belt. It took me several purchases (too small, just right-but I ruined the belt, too large and then back to the just right).

The stock replacement v-belt according to AdvanceAuto.com:
P/N 15535 (Dayco Top Cog belt) - $15 lesson
Outside Circumference: 54.07 inches
effective circumference: 53.50 inches
Width: .44 inches
Depth 7.94 mm

Dayco Top Cog: P/N 15550 ($32 Lesson - $16 x 2) - perfect and accommodates the taller DART cylinder heads with stock valve covers - raised valve cover rail surface.
Outside: 55.57 inches
Width: .44 inches
Depth: 7.94 mm

Gates 7560 - Even adjusted all the way, out the belt was sloppy ($30 lesson)
Outside: 56.58 inches


I first bought the 15535 as I run an 85 amp alternator. I could not install the belt even with the alternator off the bolts (I couldn't get it back on the bolts once belt was on the pulley).

Next, I bought the 15550 (what became the correct belt). I managed to mangle it by installing it incorrectly (it was OFF the crank pulley and riding on the damper). I ripped two layers off the effective circumference...

Thinking I should GO LARGE, I went with the Gates 7560. It was longer; beyond the limits of adjustment.

I plan to create a small project folder in my hanging 'corvette projects' folders to capture this detail. Although, I doubt I will need to replace the belt again for another 10 years given my driving habits (infrequent).

TedH

The new belt installed. The sweet smell of hydrocarbons and my roller-cammed L48.