As an ASE master tech, this video was both impressive and informative. I wish I had this when I was 17YO rebuilding my 16:1 variable Sagniaw in my Cadillac. I exchanged my leaking high-quality OE for an auto zone special that didn't last 50 years. Lessons learned.
Glad this was valuable and thanks for the feedback. I have rebuilt each of the Saginaw manual and power steering gears "by the book". The pioneer Saginaw power unit was the "Offset" design, followed by the "Inline" gears that offered a recirculating ball-and-nut arrangement. In 1959, GM introduced the Rotary Valve recirculating ball and power rack piston gear that we know commonly today. If you're curious about GM's power steering gear history, I did an article for the magazine at: 4wdmechanix.com/trailer-rebuilding-saginaw-rotary-valve-integral-power-steering-gear/.
This video is amazing. As a doubt, should we remove the play with the sector shaft adjustment, even when the stub shaft is fully turned left and right? Because this play increases with the turning of the stub shaft (steering wheel).
Glad this helps...The play is only removed over the dead center point of the gear. There is a "high point" here on the sector mesh where a specified, slight drag is measured as shown in the video. If you attempt to remove play (backlash) at the left or right steering extremes, the gear will bind over the center. The play at the two extremes (left or right) is "normal" as long as the over-center slight drag is properly established. All of this assumes that the power rack's bearing race, the ball bearings, the worm shaft bearing groove, the power rack teeth and the sector teeth are in good condition and within specification. If you're puzzled why play is "okay" at the two extremes, the front wheel caster angle and other steering geometry create resistance that removes the backlash in actual service...When the front end is aligned properly (especially caster), the wheels want to return to center naturally. This force removes the left/right extremes play or backlash within the steering gear.
Sir, I am your subscriber from Indonesia, I want to consult with you, does the worm steer have something called a TORQUE ROD? What is its function actually? Because I have a Worm Steer for an Isuzu Trooper Diesel car where my steer is already heavy and I have replaced the Seal Kit but it is still heavy, the information I got had to be checked on the TORQUE RODS and the TORQUE RODS were modified using a lathe so they are usually lighter Turn the steering wheel of the car. So far this has not been discussed with you. function and use of automotive tubes. ? Thank you, I'm waiting for the answer
A Saginaw rotary valve power steering gear senses (measures) the vehicle load or steering wheel force by way of a torsion bar that runs inside the gear's hollow stub shaft. The torsion bar is pinned to the stub shaft's upper splined end; the pin can be seen at the coupler splines with the coupler removed. (The torsion bar can be seen at the top of the splined stub shaft.) The torsion bar runs through the hollow stub shaft and into the valve body's end cap. The torsion bar is pinned to the end cap. The torsion or twisting resistance is between the stub shaft's splined section and the valve body end cap. The end cap mates with the spool valve. The spool valve helps direct pressurized fluid to one side or the other of the rack piston. This pressurized fluid from the valve body assembly provides the power assist...Usually, the valve body requires nothing more than thorough cleaning. The torsion bar is seldom an issue or weak component. When there is a clear problem like the torque to move the spool valve is too light, the stub shaft assembly (including the torsion bar and end cap) would be replaced as a unit...I have never modified or machined a stub shaft's torsion bar and do not recommend doing so. There are other ways to increase the power assist and make the steering "easier". Heavy steering, especially at low engine speeds, usually has other causes. First, I would test the power steering pump to make sure it is producing the right pressure with the engine at an idle speed. This is when the vehicle is parked and needs the most power assist. A weak pump or low pressure setting (valving issue) could create too little power assist at low engine speeds. The other issue is flow or fluid volume even if the pump produces the right pressure. Flow can be restricted by a deteriorating hose, kinked hose, defective valves at the gear's fluid inlet and outlet, or a restriction within the steering gear. Both the pressure and return hoses must be in good condition...Increasing the pump pressure and volume could make steering lighter, but too much pressure is not good, either. It can damage seals or rupture a pressure hose. If the gear has been assembled properly and is sealing well, the pump may be at fault. If the gear is worn or has been rebuilt improperly, the Teflon rings may not be sealing properly at the valve body or between the rack piston and the steering gear's bore. A pressure loss here would decrease the power assist and make the steering feel heavy.
As an ASE master tech, this video was both impressive and informative. I wish I had this when I was 17YO rebuilding my 16:1 variable Sagniaw in my Cadillac. I exchanged my leaking high-quality OE for an auto zone special that didn't last 50 years. Lessons learned.
Glad this was valuable and thanks for the feedback. I have rebuilt each of the Saginaw manual and power steering gears "by the book". The pioneer Saginaw power unit was the "Offset" design, followed by the "Inline" gears that offered a recirculating ball-and-nut arrangement. In 1959, GM introduced the Rotary Valve recirculating ball and power rack piston gear that we know commonly today. If you're curious about GM's power steering gear history, I did an article for the magazine at: 4wdmechanix.com/trailer-rebuilding-saginaw-rotary-valve-integral-power-steering-gear/.
Thank you 🙏
You're welcome, glad this video is helpful!
This video is amazing. As a doubt, should we remove the play with the sector shaft adjustment, even when the stub shaft is fully turned left and right? Because this play increases with the turning of the stub shaft (steering wheel).
Glad this helps...The play is only removed over the dead center point of the gear. There is a "high point" here on the sector mesh where a specified, slight drag is measured as shown in the video. If you attempt to remove play (backlash) at the left or right steering extremes, the gear will bind over the center. The play at the two extremes (left or right) is "normal" as long as the over-center slight drag is properly established. All of this assumes that the power rack's bearing race, the ball bearings, the worm shaft bearing groove, the power rack teeth and the sector teeth are in good condition and within specification. If you're puzzled why play is "okay" at the two extremes, the front wheel caster angle and other steering geometry create resistance that removes the backlash in actual service...When the front end is aligned properly (especially caster), the wheels want to return to center naturally. This force removes the left/right extremes play or backlash within the steering gear.
Just WOW!
Glad this helped...
Sir, I am your subscriber from Indonesia, I want to consult with you, does the worm steer have something called a TORQUE ROD? What is its function actually? Because I have a Worm Steer for an Isuzu Trooper Diesel car where my steer is already heavy and I have replaced the Seal Kit but it is still heavy, the information I got had to be checked on the TORQUE RODS and the TORQUE RODS were modified using a lathe so they are usually lighter Turn the steering wheel of the car. So far this has not been discussed with you. function and use of automotive tubes. ? Thank you, I'm waiting for the answer
A Saginaw rotary valve power steering gear senses (measures) the vehicle load or steering wheel force by way of a torsion bar that runs inside the gear's hollow stub shaft. The torsion bar is pinned to the stub shaft's upper splined end; the pin can be seen at the coupler splines with the coupler removed. (The torsion bar can be seen at the top of the splined stub shaft.) The torsion bar runs through the hollow stub shaft and into the valve body's end cap. The torsion bar is pinned to the end cap. The torsion or twisting resistance is between the stub shaft's splined section and the valve body end cap. The end cap mates with the spool valve. The spool valve helps direct pressurized fluid to one side or the other of the rack piston. This pressurized fluid from the valve body assembly provides the power assist...Usually, the valve body requires nothing more than thorough cleaning. The torsion bar is seldom an issue or weak component. When there is a clear problem like the torque to move the spool valve is too light, the stub shaft assembly (including the torsion bar and end cap) would be replaced as a unit...I have never modified or machined a stub shaft's torsion bar and do not recommend doing so. There are other ways to increase the power assist and make the steering "easier". Heavy steering, especially at low engine speeds, usually has other causes. First, I would test the power steering pump to make sure it is producing the right pressure with the engine at an idle speed. This is when the vehicle is parked and needs the most power assist. A weak pump or low pressure setting (valving issue) could create too little power assist at low engine speeds. The other issue is flow or fluid volume even if the pump produces the right pressure. Flow can be restricted by a deteriorating hose, kinked hose, defective valves at the gear's fluid inlet and outlet, or a restriction within the steering gear. Both the pressure and return hoses must be in good condition...Increasing the pump pressure and volume could make steering lighter, but too much pressure is not good, either. It can damage seals or rupture a pressure hose. If the gear has been assembled properly and is sealing well, the pump may be at fault. If the gear is worn or has been rebuilt improperly, the Teflon rings may not be sealing properly at the valve body or between the rack piston and the steering gear's bore. A pressure loss here would decrease the power assist and make the steering feel heavy.