Whenever I speed up to around 45-55 I start getting a pulsing vibration/hum from the front. I took it to the nissan dealership and they found that the left hub assembly was gone however after replacing it ( the hub) this pulsing vibration is still there. Any ideas?

 

1) wheel/tire out of balance
2) wheel not mounted correctly
3) wheel damaged
4) tire out-of-round or damaged

 

Put it on a lift and check the front end and see where the play is. How are the tires?

 

I've done literally almost everything and they said my wheels on the left are slightly bent. However the tread on the front tires seems fine.
Any chance it's unusual wear on the front side?
I also recently flew off of an exit ramp which is why my wheel hub assembly was damaged or at least I think.

 

Why bother driving when you are capable of FLIGHT?!

 

So you have bent rims, get new ones.

 

So a bent rim would make a pulsing vibration?