What's this noise when I try to start my Jeep? Video below.

jeep

#1

Just finished doing a bunch of work over the last few days.
Dropped oil and transmission pans, new gaskets on both.
New oil and transmission fluid
Four new shocks.
Took off the rear drive shave and replaced a ujoint.
Drained and refilled front diff and new gasket
Drivers side valve cover gasket
Neutral Safety switch
And I think that’s it…; what could I have messed up to cause this grinding noise? Any ideas? I’ll pull off the air cleaner cover in a little bit and see if it is coming from there. Had that off at one point, maybe I put it on wrong? Also had to drop the starter and reinstall but the noise is after it’s started. It does make a sound similar to a bad starter though.
Also, doesn’t ‘hold’ a start. As soon as I take my foot off the gas, it dies.
https://www.youtube.com/watch