60hp omc lower unit / water pump help

[plumbertuck]

I have a 1986, 60 hp johnson with a disabled vro, I am now using mixed gas. The water pump has never been serviced, I need to change the pump impeller in the, following the shop manual, I drained oil, pulled shift rod pin, removed prop and all bolts, the lower gearcase started to drop out( it moved 1-1/2")it won't go any further,it seems to be hanging up on the shift rod, What am I missing ?