t5 rebuilding

Not really. You'll never spin it fast enough to see if it grinds, or in my case with my rebuilds...leaks.

Usually you can visually inspect the gears and blocker rings and see if they are worn, but you can't see INSIDE the synchro sliders to see if those are banged up without taking the mainshaft apart.

If you rebuild it, it still may look good but really no way to test them. My last two rebuilds shifted fine, but had leaks and i had to take the trans out and reseal the input retainer