Our pulleys are designed to fit the stock Mitsubishi made OEM alternator, which there is no problem.

It has been brought to our attention that there is an issue installing our alternator pulley on aftermarket "high" output alternators. So we decided to see what the problem was.

Upon initial inspection the alternators seem very similar, with just some cosmetic differences. However once the pulley is removed, the differences are more obvious.

OEM is on the left



OEM with pulley removed



Aftermarket with pulley removed



Stock pulley (left) compared to the pulley supplied with the aftermarket alternator we purchased. It is a little hard to see in the pic, but the OE pulley is .3 mm shorter. This small difference causes the pulley to bind on the housing, which you can see created the scrape marks on the alternator housing.



The solution is a 18mm ID x 25mm OD x .3 mm shim that is available at McMaster-Carr 98089A311

Shim installed



Pulley installed



In the interest of helping out the community, even though this is not a design flaw or a problem created by our part. Anyone that has purchased one of our FD pulley kits that has had an issue with installation on a Non-OEM alternator can contact us via email and we will mail you out a shim.

Disclaimer: We have not measured the pulleys from every aftermarket alternator being sold, we do not know if some may require a thicker (.5mm?) shim.