drivin me nuts, the latch on the LH side of my tailgate started squeaking when I drive over bumps, simple fix I thought, a litte spray lube, problem solved... for 2 days, then started again, so I sprayed more, soaked it down good, same thing again couple days later does anyone have this problem or know what might be the problem, if there is something I might need to adjust etc?

 

Long story short, try this...
Open tailgate 45 degrees and slide it away from the squeak(should move .5-1 inch). Close tailgate. Check squeak.

The long version
I have a 02 sport trac. I bought it new in 02. I have had this problem for most of the life of my truck. I have lubed all the moving parts and joints only for it to come back. It wasn't until last week that I may have solved my problem. I always thought that my problem was in the latches. I could have sworn the sound was coming from that area. My gf likes to sit on my tailgate and smoke after leaving places, shopping, eating, visiting, which kinda pissed me off cause when I would close the tailgate just right it wouldn't squeak for a little while. Then she would open it and that position was now gone and back were the squeaks. I started hearing the squeaks not in the latches but in the hinges at the base of the tailgate. I pulled loose the tailgate to investigate, didn't see anything out of the ordinary. I put it back on. Still heard the squeak. Then I did something, something that seamed to fix my problem. With the gate open and about 45 degrees I pushed it to the side. It slid about half an inch to an inch. I was trying to see if I could see anything in the hinge. I couldn't, so I closed the tailgate without sliding it back. No squeak. I was in shock. I opened it up and pushed it back. Squeak. Opened it up and pushed it away from the squeak again, no squeak. THANK YOU JESUS! I hated that squeak so much. I love driving with all my windows down, including the sliding rear. But that squeak pissed me off so much I couldn't take it and would close my window. My girlfriend always said just ignore it. But I couldn't. It angered me so much. It was like it was stabbing my brain every single bump. I hope this helps. Let me know

 

remove the TG and line the hinge hole a tad bit of grease followed by a couple layers of dryer sheet and reinstall, trim excess ...

... the sheets will also help hold in the grease in the future.

Works for trailer hitch ball lube too, even without the grease added for a mess free hook / unhook experience.

 

The tailgate is too loose. I just fixed mine this evening:

1. Remove inner tailgate cover (8 Torx screws)
2. Un-clip the two green clips in the handle mechanism holding the connecting bars
3. Pull the bars up out of the clip and move them over ~1/4" so they're tighter. The threads on the bars match up with threads in the clip to lock in place.
4. Close the tailgate and test. Adjust the bars until the sound is gone and the tailgate stays shut.

While you have the tailgate cover off, lube all moving parts. Don't forget to pop the two black clips out (picture of one side below) and lube them so your handle doesn't squeak. Also lube the tailgate lift support (shown in picture below).