I had the exact same issue on an identical Edson pedestal. It slowly grew worse over time until I could barely engage the transmission. Please see the post below (post 4 outlines my solution but there are other ideas included in the thread). In my case it was neither the cable or linkage. It turned out to be corrosion/accumulation of salt and dirt where the transmission lever shaft passes through the pedestal. Edson directed me to disassemble and clean the shaft and sleeve housing. After which, it worked like new and still does.
http://forums.sailboatowners.com/index.php?threads/trans-shifts-hard.178130/#post-1283030
BTW, I installed the extended lever at the pedestal for convenience sake. Very nice upgrade.
http://forums.sailboatowners.com/index.php?threads/trans-shifts-hard.178130/#post-1283030
BTW, I installed the extended lever at the pedestal for convenience sake. Very nice upgrade.