Diagram reference number 18 in the image below:
" Fitment: 2009 NISSAN TITAN XE - 4 door

Application Notes:

Category: Body

SubCategory: Tailgate

Position: General

Part Number: 90450ZH000


This is a Tailgate Lift Support that fits the 2009 NISSAN TITAN XE - 4 door with the VK56DE engine. The Tailgate Lift Support is designed by NISSAN to be part of the Body-Tailgate. The Tailgate Lift Support has a position on the vehicle of General. The 2009 NISSAN TITAN Tailgate Lift Support is a factory made NISSAN OEM part and it comes with a 12 month 12,000 mile warranty (parts only). Do not be fooled by an aftermarket NISSAN TITAN Tailgate Lift Support! Buy a factory NISSAN part and receive peace of mind!
This factory part has a part number of 90450ZH000.