Technical SBC 350 Belt Alternator belt issue

I'm reaching out to the chevy guru crowd. I'm completely stumped. I have a slightly overstock 350 with only has a mild cam in it. I keep shredding alternator belts, never the power steering, always the alternator. I've replaced the alternator brackets, water pump, water pump pulley, crank pulley, and the alternator pulley. It keeps doing it, I've watched the belt and from the naked eye it looks to be running straight as an arrow. Like I said, I'm at the end of my rope and don't know what else to do.

 

Alternator seizing under load? Alternator mounted on right side or left side? Maybe a pic of your set up would help.

 

First we need pictures, then we need video...mount a gopro (or a phone) on something on the front of the car, and go for a drive, get on it a bit.

If it shreds belts then something is wrong, and you haven't figured it out, and we can't see the car...pictures! lots of them, clear, large, detailed, showing everything from several different angles

 

As requested, here are a few pictures of the setup.








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Video pending


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Shredding or just fraying? HRP

 

Shredding, pieces missing, internal cord visible, outer strap snapped.


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Looks like the crank and water pump pulleys are not in line? crank pulley stick out further? but that may be because of the angle of the picture?

 

It's the angle, might not have gotten it perfect. The belt seems to run straight as an arrow. How do you post video?


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Pic #1 shows the alternator backward, misaligned with the water pump pulley. Line those two up and you may be O.K.
I'd make a nice 1/8" thick steel plate to go around the bolt circle of that water pump pulley, too.
(the stock Chevy fan's base was a good seating surface for that circle of 5/16" bolts...)
Pick-n-Pull will have a Chevy with a 'flex-fan'. Buy it and shave the outer perimeter, losing the aluminum or fiberglass flex blades.

 

In photo 1 it sure looks like the lower pulley is sticking out forward close to 1/4" further than the upper pulley. That could be part of the problem.

click on the little "film" icon, and paste in the url of the video

 

I would have to say the alternator isnt lined up 100% true. Especially if thats the only belt getting messed up. If it was the crank or waterp pump pulley then the other belt would be too.


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In photo 1, I can see a slight, but clear misalignment of the alternator to water pump pulley. I had the same problem with my car, the problem was in the chrome alternator brackets, which did not fit the aftermarket intake manifold. After a few attempts to repair it, I purchased a summit racing aluminum alternator mount, which immediately fixed the problem.
http://www.summitracing.com/parts/sme-2000/overview/

 

Check and make sure there is not a burr in the grooves of one of the pulleys.

 

X

X2
Pic 1and 3 show a crank pulley out too far. Doubt the angle is off on both those pics. If you look at the belt, its going around the pulley and towards the front bumper as. I pic one its from the alt down to the crank & pic three is from the wp to the crank.

No matter what you think, it's not straight as an arrow or it would not be shredding the belt. Other possible causes would be overly obvious.

 

https://www.facebook.com/video.php?v=10152272482354685

 

I would check with my parts guy and get a narrower belt, your belt seems to be too wide and is cutting the edge, check the depth of your pullies, we throw stock pullies on with after market and a lot of times they aren't the same and don't work right. Good Luck

 

The alternator belt looks to be the correct width, the power steering belt is too wide. Those pulleys require 7/16" wide belts.

You'll note that a couple of us guys can see the misalignment that you can't see...we've learned the hard way that the pulleys need to be in perfect alignment. It's difficult to see this, it take practice.

and the video doesn't show up here, you need to post it to youtube if you want us to see it. facebook is not very good about sharing content

 

So I need to shim what exactly? I'm not touching the power steering belt, nothing's wrong with it, I refuse to fix what isn't broken. Plus I know that if I mess with it it'll never forgive me. What's easier, shimming this till it works or finding an eBay serpentine setup?


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In this photo it looks like your crank pulley sticks out,look at the belt it is not inline. HRP

 

So I should push the water pump pulley out a bit HRP?


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Here's the YouTube link
http://youtu.be/awMaDF48AOk

 

YouTube says-
" This video is private"

 

"This video is private.
Sorry about that."


I don't know what the best way to fix it....I'd probably start with some old OEM pulleys, if I were working on it.

 

Ill bet your crank pulley doesn't match and is the problem.

I'm not sure your grasping the concept here.
Belt rule #1 - they must track in relatively true and perfect alignment .

Belt rule #2 - the belts must match the pulley size & all pulleys must match.

Since it really looks like the crank pulley is out too far towards the front bumper what you need to do is move it back towards the rear. It looks like this from 2 pictures. Crank pulley also looks like its a machined pulley and the others are stamped with a mix of GM and china. I'd bet the grooves on the crank pulley are further apart than on the water pump so really only 1/2 of the crank pulley is wrong. But that makes the entire pulley wrong unless you only want to use 1/2 of it.

If you want to fix this by shimming, the alternator needs shimmed out to match crank, the water pump needs shimmed or a different pulley to match the crank spacing. Shimming the water pump is likely to screw up the PS.

And your ps belt is too wide and riding over the water pump pulley.

 

Well, let's try again shall we?



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It does look like the alternator pulley has a slight "twist" to it. It's more obvious when you look at the bottom of the pulley in the first pic. Alternator not mounted squarely?

Backward?

 

Make sure that none of your pulleys are bent or burred, then go to an office supply store and get yourself a small laser pointer (the kind that looks sort of like a penlight flashlight), set it evenly in the groove of your water pump pulley and then swivel the pulley around to point at your other pulleys. The laser should hit dead center in the groove on the other ones. This will help you see and correct any misalignment.

 

Not sure of this theory ? The PS belt is to large and riding on the top edge of the pulley and the other belt riding down in it's grove and would have the effect of two different size pulleys working against each other. The larger having more leverage is tearing up the smaller ?? Match the belts and I think you will be ok

 

This little tid bit phenomenon can not be ignored.

How about a shot from the crank up ?
Or at least a better shot of the crank pulley