To me, it's sounding like the gear setup might be bad or the pinion is locked.
I'd pull the 3rd and put it on a bench and see if you can spin it then.
If it did have a crush sleeve, you could of over tightened it and locked the pinion in there.
Crush sleeves start to crush at a really high torque number, I've seen 300-600lbs before but once they start crushing or are crushed, they go very easily.