Adjusting steering wheel play
I’ve spent some time restoring a 1966 Ford F-100 Custom. While doing this restoration I was trying to keep true to the truck’s original looks while making the creature comforts more like those of a newer truck. One item that I replaced was the manual steering system. I modified and installed a power steering unit from a 1978 F-150, which works quite well in the 1966 F-100.
One concern that I still have is the amount of steering wheel play that exists even though everything has been reconditioned. Would it be possible to replace the “truck” Saginaw steering gear with a “car” Saginaw steering gear to reduce the steering wheel play?
Implicit in your question is an assumption that a steering gear out of a car will have inherently less play than a comparable steering gear out of a truck and I don’t think that’s true. Instead, it seems likely to me that the play in the steering wheel that you’re experiencing is due to improper adjustment and/or wear somewhere in your truck’s steering system.
To adjust the over-center preload of the steering box, disconnect the pitman arm from the sector shaft and then disconnect and cap the fluid return line at the reservoir. Place the end of the return line in a container and move the steering wheel back and forth in both directions to expel the fluid from the gear. Turn the steering wheel to 45-degrees from the left stop and measure the torque (at the steering wheel nut) required to turn 1/8-turn from there. Determine the torque required to turn the steering gear through the center position. Loosen the adjusting screw locknut and turn the adjusting screw to obtain a torque reading of 11-12 in.-lbs. greater than the torque 45-degrees from the stop. Hold the adjusting screw while tightening the locknut to prevent the adjusting screw from moving and thus changing the adjustment. Install the pitman arm and steering wheel hub cover. Then connect the fluid return line and fill the reservoir with new power steering fluid.
If the adjustment doesn’t solve your problem, then there is most likely wear in the steering system.
You state that “everything has been reconditioned” but is that accurate? Has the 30-year-old power steering gear you’ve installed been completely rebuilt with new internal parts? Are the inner and outer tie rod ends, idler arm, center link, pitman arm, and other parts in the steering linkage in like-new condition?