i've been spoiled with having concrete floors

For goodness sake, remove all the rust and rubbish from the bore of the gear, then machine the carrier to size! It should be a press fit.

I'm sure the chip will break before that tap does...

someone mess up when making the keyway?

ہمارے پاکستان میں بہت ٹیلینٹ ہے مگر یہاں پر حوصلہ افزائی نہیں کی جاتی

Why not use the drill press to tap the holes?

Nggak jelas.