Serpentine belt problems with High Output alternator

[john.mulvehill 10+ year member]

Hello,

I own a 2008 Pontiac G8 GT. I had a new alternator installed that puts out 290 Amps. It came with a pulley that is smaller than the pulley that was on the stock alternator. However, the alternator place said that this shouldn't be any problem at all.

After the audio shop put in the new alternator, they put the stock belt back on. I heard squeaking at idle and more squeaking upon acceleration. I called the alternator store that I bought the alternator from and they said that I should buy a serpentine belt that is 0.5" smaller than the stock size so that it is tighter. They said the squeak is the belt slipping and that that is happening because I am using my stock belt. There are 30k miles on the car and it is still the original belt. They also mentioned that taking the stock belt off to put on the new alternator and then putting that same belt back on again could cause some stretching as well. They said that these factors, along with the fact that a smaller pulley is on the new alternator, could be causing the belt to slip.

So, after dealing with the squeaking for 3-4 weeks, I bought a Gates belt (brand they recommended) that was 3/8" smaller than my stock belt. I bought a 76.5" Gates belt and my stock belt was 76 7/8". I had it put on on Saturday and the squeak went away completely. I drove it for 3 days and then today on the way home from work I heard tons of flapping under the hood. I pulled over and saw that the belt was fraying. I had the car towed to a dealership.

Assuming the dealership will even do any work on the car with an aftermarket alternator in there, should I have a stock belt put on? Should I request that a smaller than stock belt be put on? Any ideas why the new belt frayed? Here is a picture of what it looks like

I am wondering if the belt was too wide for the pulley and maybe this wasn't a problem with the stock belt since it was slipping. Then, when the new belt was put on and it was tighter, could this have caused the fraying with the belt being too wide? Or were the pulleys misaligned?

Any help would be greatly appreciated!!!!

Thanks!

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[Louisiana_CRX 5,000+ posts]

put some belt dressing on the stock belt.....

 

[I Like Waffle]

Looks like the belt you put on was the wrong groove type. Pull the frayed part off and keep it moving

 

[Haunz 10+ year member]

try another belt...

 

[UMGixxer 10+ year member]

u bought the wrong belt, has too many grooves so as stated above rip off the excess and keep rolling or buy a new belt with the correct grooves

 

[audiophile831 10+ year member]

May be a defective belt.. Return it and get a new one. Check your tensioner too while ur at it

 

[taylorpro 10+ year member]

yep this is likely a 6 groove and you only need a 5 or so. it ripped the extra rib off and kept going. check the stock belt for the number of grooves, and go back and get one the same length as this one, but with the right amount of grooves. and you'll be fine