The pulley sheared off my alternator on the way to work this morning which was a little bit inconvenient to say the least so off to my local motor factors i went.
Parts arrived in the shop at 10:30 ordered at 8:30 all excited i rush home and fitted it, the new one fits perfectly all the bolt holes match and all was well until i tried to fit the drive belt only to find that its now massively short id need about 2 more inches just to get the belt over with the tensioner wound all the way back. I dont have the old one for reference as i exchanged it in the shop.
I went back to the shop to see if alternators came with different size pulleys and explained that my belt was now too short and was told that they are a standard size. I can only assume that i have some sort of different variant of alternator and it all bolted up fine. I had a look on VADIS and there are two different part numbers depending on chassis number but the diagrams are the same apparently the one I need is P/N 8601699 but whats difference between that and 8602138 as they are both 120A?

Any one who can tell me the difference between them gets a gold star lol