I have found that binding the steel rod ends to a piece of stiff 1/4" square balsa strip and adjusting the length of the whole thing just long enough to reach from the servo to the moving surface horn results in a friction free pushrod every time. I'm told that the idea is really old fashioned and not much used these days, as the modern stuff is so much better, but since the wooden pushrod expands the same rate as the fuselage, so no trim changes with temp changes, absolutely no friction other than the clevis pin friction in the horn and servo arm, and really light weight, I find that as a solution it is somewhat better than anything else...Sometimes 'New and Improved', isn't. And I don't have to get down the fuselage to attach it to wherever to keep it straight...
Then again, I might just be a bit of an old Luddite...
Evan, WB #12.