Alright I see how the gear comes off. When you say big and small gear what are you talking about? The main output gear? Or is there another gear I am not aware of?

My question is for that gear.. Do I need the whole shaft or can I just replace the gear on that one too?

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2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k