85 Wagon halfshaft question

[ashedd]

So my brother went and picked up my new winter mobile, an 85 Wagon. He says it sounds like someone is hitting the driver rear wheel with a hammer but that it goes away after a while. I was told by the previous owner that it likely needed new half shaft(s). I am nowhere near the car and will not be for a few months.

When I look on fastlane and such they list Homokinetic, Annular. I have no idea what any of that means. Allparts lists all these shims and stuff. I just want to know what I need to replace the drivers side half shaft. I will take a look at it and see if I think it needs a driveshaft or not before buying.