[Scott358]

The following are some thoughts, where if I'm understanding you correctly, you're asking about using a "live" threaded rod with a wheel fixed to the end, running through a roller bearing.

Assuming the roller bearing is running on the threaded rod itself....
As you may already know, roller bearings are designed to run on hardened "smooth" shafts. Being that the threaded rod is most likely not hardened, and obviously not smooth, I would suggest it be avoided, as there will most likely be bearing issues.

Regardless of whether or not the roller bearing is running on the threaded rod...
You'll have a pretty high stress concentration at the "v" of the threads (since you'll have a cantilevered load), so depending upon the diameter of the threaded rod, the distance from the bearing, and the load, you'll possibly cause fatigue failure of the threaded rod (since it's a live axle).

While it may work at first, it then becomes a question of how long. If it were me, and I had an alternative (which you stated you do), I would not risk my drive train.

Maybe I'm a bit conservative, but that's my 0.02.