I swapped the whole rear end assembly for a nearly bolt in ATC250 rear end months back.

Been running fine (according to me). This morning I noticed some Shuttering from rear when in gear and going. Slow mostly.
I only drive slow mostly.

When I spin the tires raised off ground in neutral I still hear slight clunking. Not spinning real smooth.

This is video of me spinning rear wheels manually while engine off, tires raised, and in gear….
https://goo.gl/photos/QP9Gr4guZf4Yctkf7

When it’s in neutral and being spun the sound seems to come right from the rear diff. Can post that vid shortly.

Thanks for the help.
Hope it isnt the tranny.
Too nice out for this shit 😉