Power steering input shaft free play

[dmjlambert]

Hi Folks,
I have a 1969 CST/10 with power steering.

I followed this procedure from TX Firefighter to replace the input shaft and pitman shaft seals on my power steering gear box.

http://67-72chevytrucks.com/vboard/s...d.php?t=619634

It is back in the truck and working, and it doesn't leak any more.

I have a question about the steering gear that I wonder if some of you folks have experience with. I have more free play in the input shaft than I had before the seal replacement. The shaft moves freely over a certain amount of range. I have to turn the steering wheel past this amount of free movement before the pitman arm moves to steer the truck. I had a much smaller amount of this free play before replacing the seals.

steering input shaft free play - YouTube

When doing the TX Firefighter procedure I put the adjusting plug back in, screwed it down and then backed it off a little and put the locking ring on. I am reading the overhaul manual regarding this adjusting plug, and I don't understand what the adjusting plug adjusts.

I do recognize a difference in procedures. When I followed the TX Firefighter procedure I turned the adjusting plug until I could feel it making contact and backed it off. The overhaul manual says tighten the adjuster plug "up snug" and then back it off. Is this adjustment what takes out the free play in the input shaft?




I don't understand the part about measuring valve drag, and adjust thrust bearing preload to obtain 1/2 to 2 in lbs in excess of valve assembly drag. What does all this mean?