Alternator findings AUA

Joga

A2OC Donor
The alternator of my 2001 1.4 petrol (AUA) was starting to be noisy, with typical bearing noises.
So I started looking for a replacement alternator.
The alternator in the car was a Bosch 90A unit, with part no 037 903 025 F. As we will see the ending letter is important.

After searching Bosch litterature online

, I concluded that the Bosch part 0 124 325 003 would be the correct replacement, with the alternative 0 986 041 500.

I then searched online shops and found a brand new 0 986 041 500 alternator for under 200 Euro.
Deal.
But unfortunately when I received it it had an incorrect connector configuration. It was obvious that the two-pin connector would have clashed into the exhaust manifold.

So to save time (while communication with the online shop to refund me, which by the way is still ongoing six weeks later) I started looking into what other second hand alternators from the scrap yard I could use instead.

Original type 037 903 025 F alternators were scarce and those available were old and with many miles.
But 037 903 025 M alternators could more easily be found.

From my studies in advance and confirmed after getting my hand on a second hand M-version I concluded that the only difference is the pulley diameter.
While the F-version has a 56 mm pulley, the M-version has 50 mm pulley. But thankfully the pulleys are interchangeable, so an M-version can be modified to a F-version.
This is what I did.
The modified M-version is now mounted in my car (2001 Audi A2 1.4 petrol AUA) and all seems well.

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Regarding connector configuration, this picture illustrates the required position of the two-pin connector related to the mounting holes.
Approx 90 degree angle is the original configuration.

If this angle is smaller, e.g. 40-50 degrees it will give space problems with the exhaust manifold.

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Do not be tempted (as I was) to use a 037 903 025 T alternator if it is a Valeo part rather than a Bosch part.
It has a 50 mm pulley just as the M-version, but because the Valeo pulley and shaft is not designed as the Bosch alternators it will not be possible to swap over the 56 mm from the original alternator to this alternator. Learning money :oops:

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You could also replaced the bearings in your existing unit ( still can ). Is that an over run pulley on this alternator?
 
You could also replaced the bearings in your existing unit ( still can ). Is that an over run pulley on this alternator?
To my knowledge the four pot petrols do not have free wheel pulleys. None of my three does :) .
I have actually, yesterday evening, dismantled the old one but it took some unpleasant force without having appropriate tools. I was just curious to see how it can be done. Now it is in the big bin.
 
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