2019 TRD ORP 4.0L/2GR-FE, 1500 miles on the odo, stock, except running 265/70/17 dedicated winter tires at 36 psi. I do have the factory roof rack rails, but do not have the cross bars. I also have the sun/moon roof. I do not have running boards. I do not have the sliding rear cargo tray either.
Typically the clunk/rattle I hear comes from driving down a resurfaced paved road about 45mph and drive over a "sunken" manhole cover. Minor bumps, cracks in the road, whoop-dee-doos on any road at any speed do not cause this sound. Starting or stopping, even hard stopping, do not cause this sound to be heard. The sound is what you might expect if the rear lift gate isn't shut properly, but only at larger than minor bumps, except speed bumps at 5-10 mph do not cause the sound either.
From the drivers seat the sound appears to come from inside either the rear lift gate or left or right rear as the sound isn't always appearing to come from a single spatial area. I think this is normal since vehicles are notorious for fooling us drivers as to where noise is coming from.
I have both rear seats in the folded down position (I do not have 3rd row seating) to help identify sound location but that hasn't helped.
I checked the hydraulic lift and tool bag in the driver side rear panel and everything appears to be secured. The spare tire doesn't budge. The rear lift gate is solidly closed. The only thing in the rear cargo area is a tarp held down by a cargo net.
I'd rather spend my time fixing this than taking it to a dealer for some unknown amount of time with unknown results, even as it's under factory warranty.
Any ideas on what to look for next? Does this sound like an improperly greased slip yoke? Perhaps I need to get under the vehicle and re-torque sway bar end links and suspension stuff?
Thanks