Motorcycle Repair: Transmission removal, honda 500, trany

Question
1980s Honda 500 doing an engine swap the silver wing engine I bought has different mounts. I have to change the transmission to get the top mounting bracket.After removing all the bolts the trany seems to stop within 1/4 inch Is there a retainer on a shaft that goes through to the front? Why can I not split the trany from the engine?  

Answer
Steve, am not thoroughly sure about the details of your question, but the transmission is connected to the clutch on the front, so if you are actually changing the whole transmission and not the rear cover, that must be released.
The rear cover needs the water pump impeller removed. If you are doing this without a manual try going to http://www.powersportspro.com/partsfish/login.asp and viewing the illustrations there.

Bill Silver