I recently packed the front bearings. also replaced the steering damper. and car still vibrates steering wheel at low speed, once it passes 20 to 22 miles the car smooths out. It does not seem to be the transmission as I have run the car past first gear and it still does the same vibation.
steering wheel vibrates at about 20 miles per hour than smooths out and runs great on 1990 Mercedes-Benz 300SEL
I would re-check the front wheel bearings. It sounds like they may not be tight enough. With the front wheel off the hub should have no play in it at all yet still rotate freely.
Also don't forget to hand tighten your front lug bolts to 100 ft pounds. Over tightening them can cause a front end vibration as well.
In addition to the above, check the front wheel balance and condition of the tires.