2016 f150 roush tailgate noise from object rolling up and down when opening and closing tailgate. How do I access the LOWER panel? Upper panel is no problem but the object is inside the lower panel. Thanks.

 

Remove upper panel, take tailgate off the truck and flip it upside down. The object in question should be accessible to remove then.

 

trying to avoid removing tailgate. thanks.

 

Park on a very steep hill then? Or just detach the cables and gently lower the tailgate further than the fully open position.

 

Not too sure why you do not wish to remove the gate but that is okay.
The lower panel can't be disassembled. Well I'm sure there is some way to disassemble it but it's not something people do 'just because'.

Either remove the gate from the truck or do was mentioned above, park steep uphill and remove the cables so the gate can rest on the bumper (I think it will contact the bumper?). Use a towel or something to protect the finish. I do not recommend moving the vehicle while the tailgate cables are detached.

I'd say lower the gate to normal position, find the hill then reverse a little bit and slam on the brake to force rolling object back. Then disconnect the cables and with a bit of luck on your side, the thing will be reachable.

The most complicated part may be getting under the truck to disconnect the electrical harness. Depending on your abilities -the tailgate is fairly light and easy to manage.
If you have never removed a tailgate before, you'll want to disconnect the two cables, tilt the gate up about 45 degrees and lift the right corner away from the truck, then slide it to the right.
The owners manual has a diagram indicating what I described.

 

Be aware that there are inner dividers that will complicate just reaching in to get whatever is loose inside. There are openings that may allow you to see the object making the noise. This will be an adventure, be patient!

 

Correct. The object may have gotten into the tailgate through the wiring harness opening at the bottom and may have to come out the same way.

 

You might get lucky and the object is magnetic so try fishing for it with a magnet.

 

Thanks for all the great suggestions. Yes it should be an adventure!

 

Used a magnetic probe snaked through the electronics hole after removing the upper panel to fish out a 4" bolt that somehow found its way in to the lower panel. All done without taking off the tailgate. Guess I got lucky!