possible transmission problem

I have a 2013 Elantra, there is a noise coming from the front wheels. I was checking the wheel bearings, which appear to be OK. while I had the front on the stands I started the car and put it I drive to listen while it ran. As my son slowly accelerated, about 2000 RPM, I observed that the left side stopped turning as the noise I was hearing began. Is this normal? Took the car to the dealer he said transmission is fine. I have my doubts Please help.