Side gear play

[mongocanfly]

ok, i went back and watched the videos on a bigger screen, i thought you were seeing the backlash
that does seem like a little excessive, you can get replacement side and spider gears fairly cheap..but ive seen much worse..
ive got one at the shop thats way worse than that, but its getting a trutrac in it..

also on your tooth mesh pattern, your pinion is to deep , move and reset backlash
Used gears can be a pain