Help with driveline thud/shudder

2017 Tundra with 97k miles. Trans flushed at 80k.
I have an odd sound I haven't found described on here. Around 30 mph when accelerating from decel there is a loud thud/ shudder from below the cab. It's as if the driveline is loaded one way under decel and loads the other way upon accelerating and during that switch it thuds like there is slop somewhere. U joints look ok. Carrier bearing seems to have the normal amount of "wiggle" on the rubber bushing. Dealer did an oil change recently and advised checking the fluid level. They suspect it's been low ever since the last dealer did the trans flush.
Anyone have any other thoughts? I will gladly take them. Thanks!

 

When you say shudder, do you mean the whole truck kind of "shudders" back and forth maybe 3 or so times, around 1500-2500 RPM doing about 30 mph

 

I suppose it's more of a thud/thunk than a shudder. Hard to describe noises. Kinda feels like slop or slack being taken up between the two different loading characteristics on the drive shaft between slowing down and speeding up.

 

and it happens every time when accelerating?

 

If you can get a hold of a go pro and clamp it to the frame somewhere pointed at the driveline then recreate the issue a few times and go watch the video. I had to do this on my tacoma after a brand new set of leaf springs I got. Turns out the new leaf springs were bad and I was getting some axle wrap.

 

Only at lower speeds in traffic or approaching a red light and stepping on the accelerator before coming to a complete stop. If I slow almost to a complete stop it's not as noticeable or not there at all.

 

Chip a tooth in the ring gear?

Pull the fill plug on your diff and see what the fluid looks like. Check for flakes.

 

Without hearing or feeling it, that sounds like axel wrap/shudder from worn leaf springs. will be very obvious if you get a camera pointed at your axle and a leaf spring.

That is how I would have described what my tacoma was doing before I saw the video of it.