Some family member manually pushed and pulled the liftgate to push the stuff in the cargo area, and since then, there's a cracking sound when the liftgate is on the final inch of opening, and when it starts closing. Please see the attached video and listen to that cracking sound. I have lubricated all the joints but made no difference. I noticed the cracking sound is not from the hinge, it is from the hydraulic arm. How can I access this part?
Thanks

 

My liftgate does the same thing but it is not all the time but i close and open mine manually because my power doesn't work and i am too lazy to take it all apart. I always wonder what that cracking noise is.