[Hocrest]

There are two things that I've seen the term "driveshaft" refer to on online parts stores.
1 - The shaft between the transmission and the rear diff. This has U-Joints but probably would not effect a steering shake, it tends to cause a whole car vibration. There is one on AWD cars and none on FWD cars. On some cars it is a two piece design on others it is one piece (but still serviceable) Other terms; Propeller Shaft.

2 - The shaft between the differential (front or rear) and the wheel. This has a CV joint at the wheel end and a DOJ joint at the other. It would be more likely to affect a steering shake. A AWD car will have four of these and a FWD car will have two. Other terms; half shaft, cv axle, cv shaft.

I searched part number 28321 and it looks to be a partial number, I can't determine which part it is.