The Nissan Path

Hello All.
New to the forum and Pathfinders.
I'm the latest owner of a 98 manual transmission SE.
I'm hearing (and feeling through the shifter) a solid slamming from the rear end when the truck is in neutral and either hits a bump or I tap the brakes. When drivetrain is under load = no noise.
I've already replaced the upper rear control arm bushings, sound can be recreated at low speeds with short sharp brake taps.
While watching underneath as a freind simulates I can see the axle twisting a pretty good amount.
Local "mechanics" ideas = worn out rear end...noise is gear slop
=worn out transfer case output bearing
I will say rear end seems a tad loud, no screeching but you can hear it, also 5th gear has a prett healthy whine while accelerating.
Any other ideas? Otherwise The truck runs like a top and I'd really like to avoid just throwing spendy parts at.
Thanks
Matt

Those are all possibilities. I would start by checking the driveshaft support bearing (the rubber insulator tends to collapse or come apart as they get older) and the driveshaft U-joints.

U joints were ruled out first. Wasn't even aware this vehicle was equipped with a support bearing? Is it possible it's totally missing? Been googleing for photos and parts, found plenty of part photos but not sure where they actually go?

What about the lower control arm bushings? Did you change them?

No we didn't do the lowers because my "mechanics" said they looked fine...fast forward a couple days and am now stuck in southern California, guy at a shop took one look at the lowers and said there it is. When I got back to my home for the night (campground) I rocked the truck and now the uppers seem to have a bunch of play, so i guess they got trashed in 500 miles it took to drive down here or...I've been scammed, another lesson I suppose.