100k Toyota Highlander loud growling

Today a customer came in in a panic , several days ago she thought she heard revving in her engine , she said it sounded like the engine would not shift once she was on the highway  she was convinced that there was something terribly wrong with her transmission because she was driving it , it did not seem to want to shift.  She came in and Mr. Fix-It who is very cautious first checked the level of the transmission fluid. All was fine. Then he went to the fuse box under the hood to see if anything there was amiss, all fuses still in working order. Mr. Fix-it them went into the drivers area and opened up the fuse box under the dash, again nothing amiss.  Finally after exhausting all those things, he took it for a test drive with the vehicle owner..... they came back 10 minutes later.......wht do you think they found ?
Hints: Loud growling when steering wheel was turned to the left.....quiet when turned to the right....

I will post the answer tomorrow.


Wheel bearings!