A Mechanic was informed 36-hours after installing a nose landing gear (NLG) lower torque link on a CRJ-900; the aircraft had to return to field; due to a landing gear problem. The NLG lower torque link had been installed upside down.

Narrative

I was called back to work approximately 36-hours after the work was performed. I was told that the aircraft had to come back to the airport; due to a landing gear problem. I was informed that I had installed the bottom torque link upside down by Management. I was not aware that this part could be installed this way. I may have flipped this part inadvertently when removing it and placing it on my tool box top; to compare and make sure that the two parts matched. I now understand after having a conversation with Management; that I made a mistake. I was the only person that was assigned to the nose gear on this night. Task for removal of lower torque link; task for installation of lower torque link; task for operational test of both torque links. I suggest we look into having an arrow stamped on this part; so when it is not connected to the top torque link; that the arrow points to the top of the plane; or to the top torque link? Maybe having the top torque link with a stamped arrow on it pointing to the lower torque link and having these two arrows line up?