I recently purchased a 1986 17' Bass Tracker boat that had been setting for a couple of years. Did all the maintenance I could come up with including greasing steering parts. Still, the steering is stiffer than I would like. Boat has Rotary steering. Coming off the rotary box is a clear plastic tube with a cap on it and appears to have the end of the cable inside. Is this the lubricating point for the cable and box and if so, what lubricant do I use? Also, with the exception of when it breaks, how do you know if the entire cable should be replaced? Thanks!