Ok, I have read every post on steering gearboxes and all of Jim Shea’s papers…

Before I launch into the issue thats had me stumped for 3 solid weeks, someone please explain the following…

Since the steering gearbox is designed so the input shaft leaves the gearbox at an angle that isn't true to the centerline of the car, how can the worm gear teeth and the teeth on the pitman shaft meet at top center, while at the bottom of the pitman shaft the arm is supposed to point straight forward true to the centerline of the car?

Asked a different way, if I could just pull the pitman shaft out of the gearbox, would the center tooth of the upper 5 be pointing directly at 9 O’clock and the bottom be such that the 4 flats amidst the splines would line up at 12,3,6, and 9 O’clock? Or is there an offset to account for meeting the input shaft at its angle?

I hope at least someone understands what I am getting at because everything I have read tells me when the box centered, flat on input shaft is up, the pitman arm should be aiming straight forward. I could see that being so if the input shaft ran true to the centerline of car, but it doesnt.

 

I just ran a thread, "My 77 steering gear box". I think it's still in the first page. Lots of photos of the box disassembled.
And the Pitman arm points backwards, not forwards.

 

Also, if you actually look at a C3 steering box. You will clearly see that there is a built in offset. The shafts are by no means at 90 degrees.
Nor is it possible to simply remove the Pitman shaft.

 

I had read your thread, it was very interesting. And I realize you cant just pluck the pitman shaft out of the gearbox. But since you just had your shaft out, are confirming that the center upper tooth if the 5 gears does not line up exactly with a flat on the lower splines? That they are offset?

 

And you stating that the pitman arm points straight backwards confuses me. The arm that goes on the shaft on bottom of gearbox that fastens to the steering valve? Looks like its headed forward to me.

 

I suggest you crawl under your car and have a look.

 

Ok, obviously theres a miscommunication and I am not making myself clear. I guess I will start another thread, lay out my problem, and hope someone can point out where my issue lies.

 

Your correct, don't understand your issue. Do the gear teeth line up perfectly centered. YES.
Is the Pitman shaft on a odd angle to the input shaft. YES.
It's a ball worm drive.
But exactly what the problem with your car is. And why your so confused we do not know.
The Pitman arm has no need to be in line with the center line of the car. The Pitman arm needs to connect to the drag link and then the tie rods to hold the spindles in the correct location.
But what is your problem? Does your car not steer?

 

Ok heres the issue that has me defeated.

1972 with power steering. When I got car last summer it drove nice but blinkers didnt cancel. So a month ago I started to investigate.

With wheels straight ahead and steering wheel centered I pulled horn assembly from steering wheel hub to find chisel mark on end of column pointing left.

So I turned wheel lock to lock, came back halfway, put chisel mark to 12 oclock and pulled steering wheel and aligned chisel marks and reinstalled.

Now my steering wheel is perfect, column is centered and my blinkers work perfect. But my wheels are turned to the right.

I checked at steering coupler to find flat on bottom of steering column is at 12 oclock, as is the flat on input shaft to steering gearbox.

Climbed under to adjust tie rods and get wheels pointing straight ahead and the left has almost no thread left. And to straighten right wheel would leave almost no thread in tie rod tube.

So to verify gearbox was actually centered I removed lash screw jamb nut and the 3 screws holding top cover and spun it 180 degrees and wiped away grease so I could see the gears. And they were perfectly centered with each other where they should be when going straight down the road…except the wheels are pointing to the right.

I separated steering coupler and spun the input shaft 180 degrees counterclockwise putting the flat at 6 oclock and now my pitman arm is facing straight forward, NOW I could fine tune tie rods and get wheels perfectly straight and now tie rods are equal side to side at about 15.5 inches zerk to zerk. So The car is drivable at the moment but the gearbox is one half turn off center.

And thats where it sits. The pitman arm is the original power steering arm. Its not bent. Neither are the steering arms that bolt to spindle. No indication of a massive front end collision or bent frame. So I need someone to throw me a lifeline if anyone has read this far.

 

needs to be off. put it back to factory

 

You have a car that’s been taken apart and who knows what was done to it.

You are correct that the factory had chisel marks in the end of column and the pitman arm.

Text book theory is the box should be set to center and that is also the high lash point. Then the D-Flat ground in and the car aligned from that point.

Reality is the D-Flat and center rarely are the same.

The fact that the steering wheel was indexed on the column to compensate for possibly a replacement box or lousy rebuilt box is key to finding the answer. Add to that you loosened up the jam nut which will change the lash-if it was even correct in the first place.

If I had the box I would confirm that the sector to arm position is correct and then compare center to high lash to see where things are.

once the box is dialed in it stays in that position and the rest is from the box out.

The relationship between the center,high lash,arm center all play into the box. I have wrote and taught about this for years but I don’t do it anymore because of some people that have copied my work claiming it was their own.

Those checks along with lost motion are part of a quality build that takes time and patience.

I would pull the box and make sure it is correct first

 

Thank you for the detailed reply. I had figured it all boiled down to the gearbox.

I dont have the knowledge to determine if the gearbox is ‘right’ beyond visually centering the middle pitman shaft tooth in the center of worm gear. And when I did that the pitman arm wasnt pointing in such a way that I could get front wheels aligned.

IT APPEARS THAT THE GEARS CAN ONLY COME TOGETHER AT HIGH CENTER IN ONE POSITION. Is that correct? And if at that moment the D flat is at 12 oclock but the pitman arm isnt pointing close enough to center to align wheels, where is the discrepancy? I am happy to buy a rebuilt gearbox if that would solve this issue. Its getting close enough to spring I dont have time to pull box apart even if I was so inclined.


I suspect this box has been recently serviced or rebuilt because its full of fresh grease and splines on bottom of shaft look way to fresh compared to pitman arm that looks every bit of 50 years old.

Thus my initial inquiry about the relationship of pitman gears on top of shaft to the alignment on splines below, I was wondering if I have a recently manufactured shaft thats ‘off’. Seems remote but all I could think of.

I am grateful for the information, and I thank you.

 

Well just to bring this to a close, my suspicion was right.

My 72 had its steering box replaced at some point and the pitman shaft was manufactured with the indexing flats on the spline end machined 1 spline off from where they should have been. There was no possible way to get the car aligned with steering column and box at 12 o clock. Hope this helps someone else, took me two months to resolve.

A huge thank you to Gary Ramadei for alot of help and trouble shooting, he went above and beyond.

 

T
Thank you Jordan, it was a pleasure working with you on that odd ball issue you had.

Guys, just a note. The box on Jordan's 72 is not an original Saginaw box, it is a knock off box and as with most knockoffs it isn't made the same. When you see a steering box that kinda looks like the real one but maybe not or you're just not sure what to look for, chances are it is a knockoff. About 15-20 years ago a company was making new boxes, they didn't know how to machine the gears but built them anyway. Many vendors bought them and resold them only get them as comebacks for lousy steering. Those boxes disappeared but they are still out there and for the most part are not very good. Some don't know, some accept that loose steering is how old cars are- which is wrong.