I am cleaning and replacing the gaskets on my 25-PDVC/55SHP10 and have a question I hope someone can answer. I took the combustion blower out to clean. I removed the blower motor leaving the impeller attached. After having everything cleaned and ready to go back in to the stove I noticed that there is no type of gasket or seal around the motor shaft where it goes through the round mounting plate to the impeller. Is there one? Everything else has a gasket or seal on the blower so I can not understand why this does not. What keeps smoke from going through the hole? I did not notice any thing that looked like a seal on my work bench where I cleaned the parts. I have looked at parts diagrams but nothing shows that amount of detail. I would hate to put everything back together with out knowing. Thanks for any help you may have to offer.