Alternators and cooling shrouds... lesson learned
05-31-2011, 07:24 PM
#1
6th Gear
Thread Starter
Alternators and cooling shrouds... lesson learned
During the lengthy process of replacing the alternator on my '84 928 S, I discovered much to my considerable chagrin, that there are definitely two different alternator configurations. And two cooling shrouds that are not interchangeable. The one that was on the Valeo alternator that was on my car was part number 928 603 133 04. Not realizing this was the case, I ordered a new Bosch AL325N from Amazon. It wasn't until I was trying to put the thing on the car that I discovered the "Reman Catalog Application Notices" from Bosch.
Application Notice B-20
Replacement of the back cover duct is very important to ensure proper cooling. If the connecting air hose is split, torn or damaged, it must be replaced. Premature failure of the Alternator due to overheating will be caused by not following the described procedure and will void the warranty. There are two different Original Equipment Alternators used for this vehicle, S.E.V.Marchal and Paris=Rhone. The back cover/air duct will not interchange between the two different types.
If the Paris=Rhone alternator is used, the following Porsche parts are required:
Porsche part number-Description
928 803 133 04-Air Duct
928 603 135 02-Foam Gasket (between SRE and Duct)
928 612 865 02-Grommet Seals around wire harness where it passes through duct.
The note clearly states that the AL325N (or any Bosch alternator) requires part number 928 803 133 04. The difference in the two is the position of the cut out for the harness. The attached picture has my old alternator on the left, the Bosch on the right. The guts are 45 degrees off from each other.
I found only one reference on any parts site that talked about the difference in alternator covers. I wasn't able to find the one for the Bosch in stock anywhere.
So I ordered the new Valeo, and while waiting for it, a buddy determined that the front cover of the Bosch can be removed and rotated to make it work! ARGH! I wound up returning the Bosch anyway. Oh well. At least it was Amazon.
So, the learned lesson is to make sure the thing you're ordering is actually what you have.
Best Regards,
Jim Joslin
Application Notice B-20
Replacement of the back cover duct is very important to ensure proper cooling. If the connecting air hose is split, torn or damaged, it must be replaced. Premature failure of the Alternator due to overheating will be caused by not following the described procedure and will void the warranty. There are two different Original Equipment Alternators used for this vehicle, S.E.V.Marchal and Paris=Rhone. The back cover/air duct will not interchange between the two different types.
If the Paris=Rhone alternator is used, the following Porsche parts are required:
Porsche part number-Description
928 803 133 04-Air Duct
928 603 135 02-Foam Gasket (between SRE and Duct)
928 612 865 02-Grommet Seals around wire harness where it passes through duct.
The note clearly states that the AL325N (or any Bosch alternator) requires part number 928 803 133 04. The difference in the two is the position of the cut out for the harness. The attached picture has my old alternator on the left, the Bosch on the right. The guts are 45 degrees off from each other.
I found only one reference on any parts site that talked about the difference in alternator covers. I wasn't able to find the one for the Bosch in stock anywhere.
So I ordered the new Valeo, and while waiting for it, a buddy determined that the front cover of the Bosch can be removed and rotated to make it work! ARGH! I wound up returning the Bosch anyway. Oh well. At least it was Amazon.
So, the learned lesson is to make sure the thing you're ordering is actually what you have.
Best Regards,
Jim Joslin
