2nd Gen Non-Engine/Transmission power steering shimming warning

[timbo]

I also wanted to explain how that divider spool works. It's a flow divider plus relief valve combination. Oil flows through the hole in the main fitting and creates a pressure drop across the orifice. The spool then shifts to divert flow back to the inlet of the pump to keep a constant 3. 5 gpm no matter what rpm. The size of the orifice in the main fitting(big hole) and the LIGHT spring pressure set this. The small orifice in main fitting diverts the system pressure through a drillway in the body to the opposite side of the spool, to pressure balance it. Then the small heavy spring and ball set the relief valve pressure. This causes the spool to shift, and relieve back to inlet. DO NOT put a bunch of washers on the light spring side or the spool will not be able to shift far enough, and you will have no relief protection. THATS NOT GOOD. It Will steer great, but when it hits the steering stops the pressure will spike very high. The spring inside the spool, needs shimed to increase system pressure safely. But be careful you don't want to add to much or the spring will coilbind and back to no relief protection.