The large gear is the gear (#448) on the output shaft behind the rear cover of the transmission. It slides off but may be held on with a snap ring (#445). Pay attention as you pull the cover. There are several spacers that come first as well as the gear that drives the speedometer. The parking prawl comes out too. You will be best to replace the seal for the rear cover to prevent leaks after reassembly. This is pretty cheap too. The smaller gear (#636) is the gear on the governor itself. It too is held on with a snap ring (#637). That’s following the diagram given by Army. Nice one too, wish I’d had it when I did this. But my transmission is a bit older and different in that it didn’t have the lever to hold the governor. It had a circlip that was a bear to get off. Plus no one mentioned it in their descriptions, so I had a two day struggle before MBDoc, told me about it. You’re almost done with this and will soon be back on the road.