A word about cheap aftermarket axles
I have been chasing a very annoying vibration on my NX for about 2 months. I had done an engine swap and in the process changed a bunch of parts including the passenger side axle along with a Fidanza flywheel. This vibration would only happen at around 1900rpm and again at around 3800rpm then dissapear only to show up again at around 5600rpm. At first i blamed it on the Fidanza lightweight flywheel so i decided to switch it back to the stock one, and although the vibrations were not as strong with the stock flywheel they could still be felt. I then decided to replace my passenger side motor mount and saw little improvement. A friend suggested i changed the axle as he had seen a similar issue before with a Surtrack axle. This weekend I replaced it with a Cardone unit and Im happy to report the problem is gone. Not sure if it is common knowledge here but a few of the aftermarket axles that are available now (such as AMPI, Surtrack) are made in China and are cheaper than their rebuilt and Cardone counterparts. I only paid $35 for the AMPI axle thru rock auto and about $70 for the Cardone thru a local auto part store. Just wanted to share my experience in case other people happen to have a similar issue or are thinking of getting new axles.