Need parts confirmation

[naiku]

I need some help in confirming that I have ordered / am ordering the right parts for some maintenance I am working on. First is the differential side oil seal, is that part number 38342Q? or 38342P? (looking at courtesyparts.com)

Secondly, I ordered new axles from Advance Auto Parts. But, the passenger side one looks different. Take a look at part number 39100M:



See how it kind of has that bulging part in the middle? If you follow the arrow coming out of the Murano, its pointing right to the bulging part. Well, the axle I received from Advance Auto does not have that. It is smooth along the whole length of the shaft. I would post a link to it, but can no longer find it on their site. Do I have the wrong part? I can't figure out what the bulge part is for.

thanks.