Humming noise in 2003 cadillac

I recently had a lot of repair done to my 2003 cadillac: new bearings in both front wheels, new power steering line, rotors turned, cv axel replaced.
I also bought new Michelin “Symmetry” tires as I am taking a long trip.

I had Toyo tires with some wear and had them rotated at another place other than my mechanic’s. After that I noticed the humming noise in the front; it sounds like it is coming fron the driver’s side and is most noticeable when I drive 35 or 40 mph. My mechanic said he checked everything carefully and couldn’t figure out the problem.

Anyone know what the problem might be? I plan to go to the Cadillac dealer soon in a town 50 miles away and see if they can figure it out. I am afraid to start out on my long trip without knowing what the problem is and how to fix it. Thanks.

It in my guess would be a wheel bearing, do you pick up any buzz in the steering wheel? It may take a mechanic listening with a stethoscope to hear the problem, but at least it should still be covered by the original mechanic. I went 400 miles on a bad wheel bearing, as I was on the road trip up to the cabins, but mine was not Front Wheel drive, so transaxle did not come into play. If you notice it the shop that did the work should be able to fix it. Is it noticeable at high speed? if the sound goes away it could be a loose heat shield or exhaust connection.

Which end of the car did the older Toyo tires go to? I’ll guess the front (since newer tires should go on the rear), and I’ll guess that if you swap them to the back the humming with go with them.