[Richard]

I am posting this so it will be easy to find for someone in a future search. 

To make a very long journey short, I have been chasing excessive play or slop in the center of the steering for the last two years. 

To that end I adjusted the steering gear sector screw about ten gazillion times, using the TRW recommended method, using trial and error by adjusting at almost every rest stop, using the torque input method outlined in the TRW rebuild manual, and also using a method I made up requiring a dial indicator. I could definitely get it tight, but the play at the center was still there. 

So I went on the proverbial witch hunt. I rebuilt the box, but that really wasn't the problem. 

I found three things. 

One, and most likely the worst offender, was that the pinch bolt which clamps the steering column to the intermediate steering shaft was not tight enough. There was a wee bit of play at that connection. Doesn't seem like much, but that situation is really compounded if you study power transmission. You can have a rotating shaft with two u joints IF, and only IF, both ends are secure. Well one of the ends was not completely secure so that allows a lot more slop than you would imagine. It's easy to access, pull the leather cover off the steering column and it's right at the floor level. 

Two, I replaced the universal joints in the intermediate steering shaft. I could feel the slightest lash, and what the heck I had it on the bench while rebuilding the steering box. I looked carefully at the old u joints and the joint races were slightly brinnelled, meaning they were indented. It happens. 

Three, and this one is important. For two years I have been looking at the TRW manuals for the steering gear. They all reference a zerk fitting on the output shaft for greasing the output bearing. I NEVER found it, and I looked many times. When I got the box on the bench, it was there plain as day. And, the bearing was DRY. That's not good because it could have been binding the output shaft slightly. Probably wouldn't matter when you steered cause the hydraulics were over power any stiction, but letting the wheels self center could have been impacted if this bearing were tight. So where is this beast. If you are lying on your back looking up at the box. It will be on the side of the box facing the rear of the coach. There is only about two inches of clearance to get your hand up there. It will be at the same level as the output shaft of course. It may have a rubber cover on it so it may not feel like a zerk. There is no way that anyone would ever see this fitting and know to grease it. It is going to take a short right angle fitting on the gun to grease it. If I had any brains I would have installed a remote fitting while I had the box out.. 

After doing this work and taking a long test drive. I notice two things. One, the dead space in the middle is virtually gone. Two, the steering seems to self center much better without me having to consciously undo the steering input I just made. Or maybe I just know it has to be better after all the work I did