71 jeepster

This is my 71 J Commando, It has a transplant 231 and the turbo hydraulic 400 and a D20 T-Case and Duelmatic lever style hubs. Overall it is in the best condition I have ever seen one of these in and I even still have the funny little cigarette lighter that was original to these. I never knew what that little button did ( I don't smoke) til a few months ago when a guy at work was playing with it and it fell out into his hand. The only problem I have is with the transmission which will not shift into third gear. If anybody has any suggestions on fixing that let me know?
http://s14.photobucket.com/albums/a343/smithie128/?action=view&current=jeepster1.jpg