Posted by: @pork-chop-sandwiches

about 36 to 42 mph

I had this experience with my old FWD Buick, a wheel was out of balance.

Assuming you didn't get new tires as well during this work, is there a chance they rotated the tires, and put an out of balance wheel from the back to the front? Or maybe a weight fell off if they dropped a wheel or something?

I would also (first) verify the wheels are torqued properly like Kaizen said. And I hope they did a star pattern when reinstalling the wheels. Look up the specs, probably around 90-100 lb-ft range.  

Well I would assume it has to do with the work. Perhaps the shaft is on balance door. Something wasn't put together right when they did that work. If you trust that mechanic of them look it over. If not, go to a different mechanic. Tell him the work they did. Let them check it out

Check your lug nuts. See if they are tightened to spec. 

Checked all the lugs. The FR wheel (that would have been removed for the CV work) definitely took more muscle to loosen than the rest. After re-torquing all of them back to spec, it felt as if the wobble was gone for a bit, but then returned. 

Months prior to the CV work, the same shop did install new front tires. The rear tires were dry rotting, so the front tires (still good) and wheels went to the back. Thus, the rear wheels went to the front with the new tires. Before that swap, the old rear wheels/tires produced an audible "whom, whom" noise from one side for over a year. But its intensity depended on season, temperature, etc. Mechanic attributed it to uneven tire wear.

When I bought the vehicle, the owner had a receipt showing a RL caliper replacement. It lead me to think he ran over something pretty hard and also caused damage to that rear wheel/tire that made noise.

I am currently too far away from that shop to go back.