This topic has been discussed in lengh many times in the Forum but I can't find a good solution to my problem...

On a 1987 V6 5spd, I have changed the broken alternator belt about 5 times in the last couple of months...The water pump was replaced last November and the alternator was replaced TWICE in the last few months...I replaced it again with a new unit from Autozone last week!!! The pulley was changed from the old alternator to the new one...
The pulley spins freely on the alternator.

The alternator bracket is fine (not cracked) and the belt tension is nice and firm when first installed...The belt appears to be working fine, it does NOT wabble with NO noise or sqeel when the car is idling....I take the car out for a test drive with the new belt installed ( couple of miles) and it works fine.....The voltmeter gauge shows alternator is charging....The first time I drive the car for more than 5 miles the belt starts sqeeling and within minutes the belt breaks....The alternator is still screwed tightly on the bracket... I have tried different brands of belts and more expensive belts but the belt still breaks after a few miles of driving...

ANY ideas???

Thanks

Are there any wear marks on the sides of the belts after it breaks? You might have something out of alignment that puts sideways pressure on the belt.

things that come to mind would be an out-of-round pulley, something rubbing, or a chip/bend on the edge of a pulley. maybe the waterpump shaft is loose. when the belt breaks, is is shredded on one side, or just snapped? if the motor mounts are bad enough, I suppose the motor might move enough for the belts to hit something.

Well as you can in the photos below the belt(s) get pretty much shredded....The outside grooves are totally gone.

The pulley on the alternator looks okay to me when I spin it manually....When installed on the alternator it spins freely...The water pump pulley also looks good but it's more difficult to spin because of water resistance....When the car idles the belts looks fine and aligned on the pulleys....There is no noise coming from the belt when the car is idling...

I'd check for pulley alignment first if there are no obvious burs that could be causing chafing then failure. Were there bushings on the alternator to make it stick further out/in that weren't put back on with the replacement?? Also, bad motor mounts would be a good question to ask too. Gates recommends driving at least 15-20 miles to break in a new belt. (NO spirited take-offs, hard corners, etc.!!)

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XRacer Pro...I Feel The Need For Speed!

http://www.tekchip.com/ferrari

! wow !
thats a new belt?! arg!
the pulleys must not be lined up right, or theres something on the pulleys chewing up them grooves.

Yes, unfortunately that WAS one of the brand new belts I put on the alternator, just to have it shredded after only a few miles.....Not a good thing to get stranded and have to call for help each time...

Anyway, I think XRacer Pro might have something there....As I recall there was a small bushing on the new alternator pulley from Autozone....However I did NOT put it on when I changed the pulley (Autozone had the 6- groove pulley mounted but the Fiero uses the 5-groove pulley)....The original alternator did not have a bushing but maybe the bushing is needed to correct alignment.....I will give that a try before installing a new belt again.

Thanks - VK

Id also look carefully aroung the engine compartment for something that may be sticking out, or loose and cutting it. ie/ metal exhaust shield, piece of metal picked up off the road jammed into the cradle somewhere. Maybe a bolt like on water pump has backed out, and belt is hitting it.

[This message has been edited by rogergarrison (edited 03-29-2004).]

Does the inside of that belt feel hard and brittle?
From the photo it appears to be burned, which would indicate severe slippage or some other form of excess heat (such as an exhaust leak perhaps).

Russ

How many grooves/slots are on your pullies? Count the grooves/slots on each pulley (alternator/crank/waterpump). All of the pullies should have the same number of slots, probably 5. If one has less slots than the others, it'll shred up the belt like this (for a while I unknowingly had a 4slot pulley on my alternator with 5 slot pullies everywhere else).

-Jeff

I recently investigated my squeeling belt to root cause... I'm not shredding them like you are, but my belts will get stretched really badly to the point that they can't be tightened. What I found was that the water pump pully was moving in & out fairly significantly. I'm guessing that the alt itself is shifting or rotating left to right causing the angle on the belt to change and dragging the water pump. When I put the last belt on, I did check for play on the alt and it wasn't evident with mild hand force but I think if I would have used a prybar I would have seen it move. I should get some time this WE to look more closely at my problem. I will take pictures and post my findings if there is anything of significance. I also need to post my write-up on my variation on the temp gauge fix... Anyway back on topic, I removed the air vent from the right side, fired my car up and immediately went back there to watch the belt and alt and that's how I spotted the "dancing" belt and water pump pully show. BTW, my water pump only has about 2K miles on it and the belt didn't squeel when I first changed the water pump and belt together. Anyway, I will follow up with my findings. G/L