Serpentine belt??

[BlackRain]

Went to pepboys to get a belt. The guy asked what alternator 120 or 140? Um, dont know. I have searched, read that the OE is 100a. Only option at Pepboys is 120 or 140 belts.

How different are the belts for the different output alternators? I bought both to use one and return the other, but then I read that OE is 100a??

 

[NYrr496]

Off the top of my head, the higher output alternator uses the longer belt and vise versa. I know my truck has the standard output alternator, but I don't know if it's 100 or 120. I accidentally installed the longer belt once and it slipped.

 

[peterey2]

i had the same thing happen to me. couldnt find the exact amperage. so i ended up taking the serp. nelt in and had them match it. Stupid Pepboys.

 

[NYrr496]

I just went out and looked at my belt. Dayco Polycog 5060960. That's the short one for the standard output alternator.

 

[BlackRain]

I got the numbers off the belt, it was a GM number, but he had no idea.

 

[clean95]

ok peeps! stock is 120 ha just bought one the high output 140 alternator is for the diesel because they run dual battery's..... and there starters draw more amperage

 

[BlackRain]

Thanks for the info. Going out soon to replace, then return the other one.

 

[NYrr496]

That being said, and I believe it's correct, why don't the parts books differentiate the longer and shorter belts to the diesel and gas engines?

 

[peterey2]

thatd be using WAY too much common sense NYrr496!! haha

 

[LaCeS OuT]

I have a gas engine with the 140 amp alt in my 99 Yukon from the factory. Check your RPO codes in the glove box and it will tell you the alternator you have.

 

[John Redcorn]

why don't the parts books differentiate the longer and shorter belts to the diesel and gas engines?

Also if they catalog it by alt size that'd make you think that, weirdly, the only difference between the diesel and gas accessory system is the size of the alt pulley. (maybe it is but somehow I doubt it.)

 

[515niko]

I have a 04 tahoe with about 80,000 mls, should replace my serpentine belt now? I looked at it and it still looks good, no cracks im origenal owner.

 

[mixtapesyndicate]

the only difference between the belt sizing for a 105a (stock) and a 140a is .70 inches. Yes seven tenths of an inch.