Last year I pulled my power steering box out to replace the seals. I haven’t installed it yet and want to make sure I have all the torque settings correct. I took a bunch of pictures I will upload sometime and show a few tools I made to help. I’ve seen the great hand drawn diagram of the torque settings. I’m wondering who did that?
I would like to understand the reasoning for the torque settings used. I’ve scoured the internet and found information for the manual system but little for the power steering system. Maybe some of you can help me. I will reference the included exploded view. It was a while ago so I’m doing this from memory.
Front Bearing - steering wheel input
I think I understand the reasoning for the front bearing torque (steering wheel input). I believe it controls the sensitivity of the steering. The looser the torque on this, the lighter the steering will be. If it’s too loose the the slightest turning force on the steering wheel will turn the wheels and be too sensitive. This torque eventually moves the shuttle valve which ports the fluid to either side of the large piston (#49) which actually moves the pitman shaft (#89). Is this correct?
With this front bearing torque adjustment I believe you are adjusting the force required to rotate the piece inside the piston containing the recirc balls. This piece has a lever on its side that controls the shuttle valve. So once again I am assuming you’re JUST measuring the amount of force required to rotate the recirc unit back and forth while NOT actually moving the piston itself. Do I have that correct?
When you are adjusting the torque for the front bearing input it looks like the only thing I’m tightening is the bearing itself. Is that correct?
I believe the recirculating balls are there as a back up to the power system. If you lose hydraulic pump pressure i.e. engine quits, you can steer manually. The power system mainly bypasses the balls though.
Pitman Shaft Adjustment
The other big question I have is what does the screw adjustment (the other torque adjustment) do for you? It looks like the pitman shaft (#89) can be adjusted up and down slightly. The end that attaches to the piston (#49) is sort of a ball bushing. Why there needs to be any play in this doesn’t make sense to me. This ball bushing allows the piston to rotate slightly as the piston moves back and forth in the cylinder. Can any explain what the screw adjustment does?
I hope I was clear and thank you for any help.
Kevin
