1973 Ford 5000 with Power Steering problem

[RickHollerich]

1973 Ford 5000. Replaced power steering pump a few months ago and has been working fine. Other day, while making a right turn in reverse, front tire hit a frozen runt that caused the tire and steering wheel to turn completely to right hitting the turn limit hard. After that, I could no longer turn the wheel to the right. It would turn fine to the left, but would not move at all to the right no matter what prostion I tried it from . Once it hit the left limit, I could not move the steering wheel at all.

I have verified that the tires and front end linkage works fine once disconnected from the power steering gear box.

While working on the power steering gear box, I found that once I relieve the oil pressure in the lower gearbox, by lossening the external pipe going to it and draining some of the oil out before tightening it back up, I could steer either way without problems, hitting both limits. However, once I started the tractor and worked to remove the air from the steering system by turning the steering wheel to the right and holding it at the limit for a while, the problem returned. Turns to the left without problems, but would not move to the right at all. It acts like once the gear box fills with oil, the oil is not getting returned to the pump when trying to turn to the right.

I did remove the return line to the pump, and I do get air and a little oil coming out the return port for a few seconds then nothing when turning right.

I did tear the unit down (see pictures), and as far as I can tell, everything looks good. No broken items, all o-rings and seals look good. All the ball bearings are accounted for and look good. I did verify that all the holes in the control valve are open by blowing air through them. Anybody have some suggestions on what is causing the right turn problem?

 

[Sean in PA]

Do you get the same symptoms when the external steering arm is not connected to the linkage?

 

[Bern]

1973 Ford 5000. Replaced power steering pump a few months ago and has been working fine. Other day, while making a right turn in reverse, front tire hit a frozen runt that caused the tire and steering wheel to turn completely to right hitting the turn limit hard. After that, I could no longer turn the wheel to the right. It would turn fine to the left, but would not move at all to the right no matter what prostion I tried it from . Once it hit the left limit, I could not move the steering wheel at all.

I have verified that the tires and front end linkage works fine once disconnected from the power steering gear box.

While working on the power steering gear box, I found that once I relieve the oil pressure in the lower gearbox, by lossening the external pipe going to it and draining some of the oil out before tightening it back up, I could steer either way without problems, hitting both limits. However, once I started the tractor and worked to remove the air from the steering system by turning the steering wheel to the right and holding it at the limit for a while, the problem returned. Turns to the left without problems, but would not move to the right at all. It acts like once the gear box fills with oil, the oil is not getting returned to the pump when trying to turn to the right.

I did remove the return line to the pump, and I do get air and a little oil coming out the return port for a few seconds then nothing when turning right.

I did tear the unit down (see pictures), and as far as I can tell, everything looks good. No broken items, all o-rings and seals look good. All the ball bearings are accounted for and look good. I did verify that all the holes in the control valve are open by blowing air through them. Anybody have some suggestions on what is causing the right turn problem?

Obviously your pump is OK if it turns fine in one direction. As for the PS box itself, the only thing that comes to mind is a damaged torsion bar in the control valve, ref #11 in the image below. Make sure that the green part is centered within the slots of the red part. This can be seen visually at the top. If that looks good, clamp the screw part #8 firmly in a vice with soft jaws or wood blocks, and then use a pliers or vice grips to turn the input splines back and forth a few degrees. You should feel the input shaft want to spring itself back to neutral (center) as you relieve tension. If it doesn't do that you have a damaged torsion bar inside the control valve. This is a non-serviceable part.

 

[RickHollerich]

Do you get the same symptoms when the external steering arm is not connected to the linkage?

As mentions in my comments, the wheels and steering linkage works fine when disconnected from the steering arm. the problem is definately in the gear box.

 

[RickHollerich]

Obviously your pump is OK if it turns fine in one direction. As for the PS box itself, the only thing that comes to mind is a damaged torsion bar in the control valve, ref #11 in the image below. Make sure that the green part is centered within the slots of the red part. This can be seen visually at the top. If that looks good, clamp the screw part #8 firmly in a vice with soft jaws or wood blocks, and then use a pliers or vice grips to turn the input splines back and forth a few degrees. You should feel the input shaft want to spring itself back to neutral (center) as you relieve tension. If it doesn't do that you have a damaged torsion bar inside the control valve. This is a non-serviceable part.

Are you saying the orange part in the image is supposed to turn some? I have not tried it in a vise, but it doesn't turn at all by hand. If it is supposed to turn some, do you know what the current part number is for a replacement torsion bar? My repair and parts manuals are 50+ years old and the part numbers are way outdated. Will I also have to replace the Annular rings and/or control valve? I see no part numbers for the Annular rings in the parts book, but the repair manual shows them. Note: I attached some additional closeup pictures of my bar.

 

[Bern]

Are you saying the orange part in the image is supposed to turn some? I have not tried it in a vise, but it doesn't turn at all by hand. If it is supposed to turn some, do you know what the current part number is for a replacement torsion bar? My repair and parts manuals are 50+ years old and the part numbers are way outdated. Will I also have to replace the Annular rings and/or control valve? I see no part numbers for the Annular rings in the parts book, but the repair manual shows them. Note: I attached some additional closeup pictures of my bar.

To repeat most of what I said earlier.....clamp the lower end down, and rotate the upper part back and forth with a pliers. I don't recall now which part moves, however I can say that the green and orange parts should separate from each other, it should spring back and forth and return to a centered position when you let go. If it doesn't, something is wrong with the torsion bar. It is not serviced separately.

No need to replace the annular rings, however I would suggest a seal kit and replace all of the o-rings.

 

[RickHollerich]

To repeat most of what I said earlier.....clamp the lower end down, and rotate the upper part back and forth with a pliers. I don't recall now which part moves, however I can say that the green and orange parts should separate from each other, it should spring back and forth and return to a centered position when you let go. If it doesn't, something is wrong with the torsion bar. It is not serviced separately.

No need to replace the annular rings, however I would suggest a seal kit and replace all of the o-rings.

I will give it a try when I get a chance and report back. However, my bar does not have a notch at the top of the shaft next to the splines, as shown in your image, but at the bottom, next to the ball bearings. But I am assuming that is the same thing you mentioned, just upside down on my setup.

Also, I have not found any place that just sells the bar. Everything I found sells the bar along with the rings, as well as the piston, as a set for $1200+. If there is no bar-only option available, I am thinking it might be best to just replace the whole gearbox for $1700. At least then I don't get it all back together only to fine it doesn't fix the problem and I am out $1200.

FYI: was planning on getting the seal kit and replacing all of them if I can find the bar.

 

[Bern]

I will give it a try when I get a chance and report back. However, my bar does not have a notch at the top of the shaft next to the splines, as shown in your image, but at the bottom, next to the ball bearings. But I am assuming that is the same thing you mentioned, just upside down on my setup.

Also, I have not found any place that just sells the bar. Everything I found sells the bar along with the rings, as well as the piston, as a set for $1200+. If there is no bar-only option available, I am thinking it might be best to just replace the whole gearbox for $1700. At least then I don't get it all back together only to fine it doesn't fix the problem and I am out $1200.

FYI: was planning on getting the seal kit and replacing all of them if I can find the bar.

Is the torsion bar damaged? Does it spring back and forth?

 

[RickHollerich]

Is the torsion bar damaged? Does it spring back and forth?

if you are talking about the splines rocking back and forth, red arrow in attached image, then yes the torsion bar does appear to spring back. When I rock the splines, the little pointer inside the bar, green arrow in image, moves back and forth.

Note: the movment isn't much, but it is enough to where the pointer will move just out of view inside the hole at max twist, then spring back to the middle when I let go. It works both ways and moves easily.

If the max twist is suppose to only be a very small turn either way, then I would say the torsion bar is not damaged.

Thanks again for any help you can give me on this. Greatly appreciated.

 

[Sean in PA]

As mentions in my comments, the wheels and steering linkage works fine when disconnected from the steering arm. the problem is definately in the gear box.

Sorry, I was asking the opposite, does the gear box still have the problem when the steering arm is disconnected, but apparently that is a yes.

 

[Bern]

if you are talking about the splines rocking back and forth, red arrow in attached image, then yes the torsion bar does appear to spring back. When I rock the splines, the little pointer inside the bar, green arrow in image, moves back and forth.

Note: the movment isn't much, but it is enough to where the pointer will move just out of view inside the hole at max twist, then spring back to the middle when I let go. It works both ways and moves easily.

If the max twist is suppose to only be a very small turn either way, then I would say the torsion bar is not damaged.

Thanks again for any help you can give me on this. Greatly appreciated.

The movement is only a few degrees back and forth. It's called a rotary valve. If it has a noticeable resistance to turning, and springs back to the center position when you release it, then the torsion bar is fine. I have no other ideas for you. Any other problems related to your situation should be visible to the naked eye.

I would get a seal kit for it, check the shimming when you put it back together, and then try it again.

 

[RickHollerich]

The movement is only a few degrees back and forth. It's called a rotary valve. If it has a noticeable resistance to turning, and springs back to the center position when you release it, then the torsion bar is fine. I have no other ideas for you. Any other problems related to your situation should be visible to the naked eye.

I would get a seal kit for it, check the shimming when you put it back together, and then try it again.

Thanks for you help. My plan is, as you say, to get the seal kit, rebuild it and see what happens. If that fails, will just have to buy a complete replacement, as I can not find any place on the web that sells the internal parts.