About adjusting that steering gear. I'll assume that it is the same basic design as a car. You can't tell if it is too tight from the wheel. You can only tell if it is too loose or WAY to tight. If you look at the innards you should see that there is enormous forces in there. If it is much too tight I honestly think it could split the box open. Grim!
Here is how I did it after getting mine to tight. If you adjust for zero lash at the center where it wears the fastest, when you turn to lock you will have the gear in bind. No way to predict this. Instead, turn the wheel to lock and adjust for zero lash. Then turn back to center and see how much play you have. If it too much you must rebuild. My manuals all say that this adjustment MUST be done with the box on the bench. I always jack my front up at the wheel frame so I can manually push the wheel from lock to lock.
Does that bus have king pins? I had a tight king pin and it didn't let the wheel come back to center. Was an absolute nightmare to drive. Constant attention. Anything in the suspension that binds will give the same result.
A friend has a shop here in Eugene. He was sent a Beaver coach by Beaver to evaluate. The owner, unhappy fellow, said the thing wandered on the road and was unpleasant to drive. Ron asked me to lay under the front and look for anything unusual whuile he turned the wheel with the engine running. What I saw absolutely AMAZED me. The steering gear was mounted in this very sturdy looking welded plate steel three sided box like structure. Vert stout looking. As Ron rocked the wheel back and forth that entire box was twisting like it was made of rubber. An inch or more each way. Ron said that on the road and hitting a chuck hole it must have moved a lot more. He constructed a series of heavy duty braces for the box after he reinforced. No more movement. The owner said if he wasn't right back he was probably back on the road and things had improved. He called an hour later and said the thing drove like it was on rails. Ron called Beaver to advise them of the resolution and original problem to which the service engineer said "no sh#t


" Made a believer out of me and I advise everyone with a problem to do that analysis. It is cheap and you get a look at all the ball joints and pivot points/idler arms as well.
HTH,
John