I am having some problem with the stock pushrod tube and wire for the throttle. I have a 4 stroke up front. The oil residue from the engine enters the throttle tube and travels right up to the servo arm and spills over on to the servo tray. Over many flights, it has become dark and I feel it might give way with the oil seepin into the wood. I tried putting vaseline into the cavity between the rod and the tube, but the problem does not seem to go away. Any suggestions?

Thanks