Alternator Question

**B501S4** · 07-30-2008 01:53 PM

I just recieved an alternator that I had ordered on monday. I get the box and has the correct part number and so does the recipt. I get into the box and i see that instead of the Bosch core it is the Valeo core instead. I know that they are both 120amp and have the Bosch housing but know that I should replace the one I have with the same one. I dont know what kind of difference it makes between the two cores , maybe someone could shed some light on me as to why that is and why I cant replace my Bosch with the Valeo core I recieved. Would save me a little time but I just want to make sure it is alright to do so.

**The_Jerbel** · 07-30-2008 02:07 PM

I can't see any reason why you can't interchange them as long as the specs are the same. Audi switched suppliers in '01, which is why people think you have to use a manufacturer-specific alt.

**mholme** · 07-30-2008 02:29 PM

Originally Posted by B501S4

I just recieved an alternator that I had ordered on monday. I get the box and has the correct part number and so does the recipt. I get into the box and i see that instead of the Bosch core it is the Valeo core instead. I know that they are both 120amp and have the Bosch housing but know that I should replace the one I have with the same one. I dont know what kind of difference it makes between the two cores , maybe someone could shed some light on me as to why that is and why I cant replace my Bosch with the Valeo core I recieved. Would save me a little time but I just want to make sure it is alright to do so.

As long as it came with the correct pulley, you can use it. Bosch and Valeo use different types that are not interchangeable.

**jakecro** · 07-30-2008 02:42 PM

The pulleys are different between the two brands; the Valeo pulley is recessed where the Bosch is not. That being said, some have substituted one for the other. See link below.

http://forums.audiworld.com/s4/msgs/2831197.phtml

**B501S4** · 07-30-2008 03:09 PM

^^so with that being said there should be no problem switching out the Bosch Alternator I have now for the Valeo I got in the mail? Is the serpentine belt going to have to be replaced as well? Any other input would be great

**jakecro** · 07-30-2008 03:18 PM

I would replace the belt since it is much easier than when the radiator support is in place. If, however, the belt is fairly new I would not replace. They are relatively cheap ~$25.

**Kruat** · 07-30-2008 03:46 PM

Can't you just interchange the two pulleys?

**The_Jerbel** · 07-30-2008 04:01 PM

Definitely replace the belt, and if the tensioner has never been replaced, you may want to do that as well.

**mholme** · 07-30-2008 04:37 PM

Originally Posted by Kruat

Can't you just interchange the two pulleys?

You can switch the pulleys, but some cores don't come with a pulley and you can't put a bosch pulley on a valeo alternator, or vice versa.

**B501S4** · 07-30-2008 05:41 PM

the core I have came with a pulley on it so if it does not fit up i guess i can swap it out. i will find out tomorow

**Tiluleshpingen** · 06-11-2009 10:18 AM

Originally Posted by mholme

You can switch the pulleys, but some cores don't come with a pulley and you can't put a bosch pulley on a valeo alternator, or vice versa.

but what difference can the pulley make ?i dont get it why do we have to swap pulleys?

**Tiluleshpingen** · 06-11-2009 11:11 AM

ok ok i think i got what all the misunderstanding is.
If your car has a BOSCH alternator and you bought a VALEO one WITH the PULLEY... then its a perfect fit .If you bought one WITHOUT a PULLEY and u want to put a BOSCH pulley then it will not work as the pulley will touch and will not spin by the alternator, so what you do is Buy the VALEO PULLEY FOR THE VALEO ALTERNATOR.. i guess some of us have about alternators with out pulleys. correct me if i am wrong.