The direction for the woodcrafts "b" company "Parker style pen"instruct you to assemble the pen from the nib up.
Griz has posted instructions for assembling the pen in a different way than the WC tutorial.
The first 20 pens I turned were from this particular kit.
It is a ROYAL PITA! (for me anyway,and if not for me possible problems if the customer doesn't get the hint and continues to turn the barrel after the refill is extended)
The transmission fits inside the cap finial from the top.
If that gets stripped the pen needs to be either
disassebled or an act of God to get it apart.( you need to make a little "gear puller"
Because of the problems I and others have had with this pen I stopped making it and also due to the fact that it does not lend itself to modification.
A couple of tips.
Prior to assembling the top put the transmisson on the tranny holder.insert the top on the transmission.(no finial)
make sure the pen revolves freely with no obstruction.If you have any resistance here make sure the bottom barrel is flush with the transission holder.If it is the least bit proud, that could be your problem.
Another point of concern is the inside of the top tube.This needs to be ABSOLUTELY round so the transmission can pass through with enough clearance and no restriction.
If you look at the transmission the only point of contact is the section at the very to where it gets pressed into the final.(Or the other way around, I forget which)
Even if you do get everything correct the customer can still screw it up.
The design is Pi$$ Poor compared to other companies ( and even their own) methods of extending the refill.
It is because of these problems I don't make this style any longer.
I also like the classic look of the pen but went to a "Perfect Fit"( also by the "b" company) which has been virtually trouble free and is easily modifyable.
Here's link to the last time you posted this problem,perhaps you missed something:
http://www.penturners.org/forum/topic.asp?TOPIC_ID=7271&SearchTerms=Classic,,American
One more thought,
Try a small rattail file inside the nib occaisionally a bit of plating material gets lodged there.
if only te transmission is stiff without the other parts assembled possibly you do have a bad transmission or damaged it in assembley.From experience it doesn't take much.
If the pen doesn't work right the first time after assembly but the transmission worked fine prior to assembly chances are it was damaged while assembling.(DAMHIKT)