GP uses plastic bushings that are placed along the entire length of the 2-56 pushrods that ride inside of the outer nylon tube (just like Jerry Sigur described above). Just follow their instructions, as they describe the assembly quite well. It's a great idea in theory, but I find that it has quite a bit of drag when the pushrods are moved back and forth. I prefer a plain 2-56 rod inside of a snugger fitting nylon tube. It also helps if the routing of the pushrods is slightly bent, putting a little tension on the wire. It sounds like you may have skipped the bushing step of the installation (look for a length of splined white nylon tubing which you need to cut into short lengths).

Hope this helps.