[Vwdiesel] passat/jetta parts interchange question

[raymond greeley]

hello all, today saturday, i had a outer cv  joint failure, passenger side, on my 90 passat. the passat is a 4cyl gas conversion to diesel so some items are the lighter weight components as compared to the v6 model. i hadn't any indication (noise when turning or clicking), i was making a u turn, hard left, it made some noise then and i took note, then it let go. i looked in the side mirror and saw parts rolling. i found what i think was a bearing race, broken. better here than on the road to some where as i am planning to take this car on the road. 
searching auto hausz and other parts sources,  it appears the passat used a 100mm and the jetta used the 90mm. I ask because i have a complete jetta (for parts) that i had replaced the axles on.
i was looking for a site to check interchangeability of related parts. i am sure i will visually line them up side by side to get some idea early this week and decide whether to take the passat axle in for rebuild. 
any ideas on interchangeability.  
thanks and i hope your weather has been good. chicago, after a record breaking number of days above ninety and drought, is into a fall cool spell.
ray