I have a grinding/roaring noise coming from the.

The right bearing can be noisy and it will sound like it's the left one. The only sure way I've found to determine which one is noisy is to run it in gear on a hoist and listen next to each one with a stethoscope.

There is also a tool you might be able to borrow or rent from an auto parts store that borrows them called the "Chassis Ear". It is a set of six microphones, a switch box, and headphones. You clip the microphones to suspect points, then drive around while listening with the headphones. You can move the microphones around to zero in on the source of the noise. Be aware that many mechanics have never seen or even heard of this tool. Suspension and alignment mechanics use it to find rattles, squeaks, and other noises.