I'm trying to find the correct information for this procedure but I am having a hard time finding what I am looking for.

I am in the process of installing factory power steering in my 69' Coupe and I have a complete set-up from a donor car (75).
Since my steering box was so sloppy, I am installing the one from the donor since it's much smoother and tighter.
The problem I am having is figuring out (without opening the box) is what EXACTLY is the center point of the steering box?

My GM manuals state that on most Chevys, the 'flat' of the worm gear should be facing up but the Corvette has a scribe mark in lieu of this flat. Well the box I have DOES have a flat but I see no scribe?
Where would this scribe be?

I've already fixed the 'Bubba alignment' procedure of moving the steering wheel position on the shaft- So now my wheel scribe lines up with the shaft's scribe but when I put it all together (steering wheel straight up and worm gear flat facing up), I don't have equal travel from lock to lock?
No steering linkage is installed on the box other than the pitman arm.
I get a full 2 turns from center when I turn to left lock but I only get about 1 7/8 turns from center going to right lock. Is this an issue?

There really isn't much room for play in the rag joint (maybe 1 tooth either way) while still getting the bolt to fit so I'm trying to determine if I really have the box centered with the flat facing up of am I missing something?

Any advice and/or pictures would be most appreciated.
Thanks!
Elm

 

No one has run into this?

 

I mounted my steering box to the frame and before I attached anything to it I moved the p arm backa nd forth to simulate lock to lock on the front tires. with the front end of the gound i I hooked up everything with new ball joints everywhere. Ensure that your front tires are perectly straight and then set your steering wheel straight and connect the rag joint. If anything is off a good alignment shop will get it all correct.

Ecklers has a PDF about manual to power steering conversion. Or at least they used to

the two one direction and 1 7/8th is no big deal.

 

When the steering linkage has been completely connected, I think you'll find that it won't turn that far left and right anyway. The linkage will hit the stops first.
If you are really interested in "blueprinting" your steering system, make sure the tie rods are of equal length, with the steering straight ahead and toein to specs. This can help equalize the bump steer from side to side. You may have to adjust the amount of turns the power steering control valve has been screwed onto the center link to do this. Of course, make sure it's on far enough for safety.

 

I realize that once all the linkage is attached, the steering will never achieve the full lock to lock range as it does now.
My concern is that the box itself won't be true 'on-center' with how it is now.

So now I'm torn between assembling it with the steering wheel straight ahead and the 'flat' on the worm shaft straight up or do I adjust the worn shaft for even travel (turns) left and right regardless of where the 'flat' ends up?

Elm

 

Your gear should be "true on center" when the machined flat on the input shaft is at 12 o'clock. This paper should answer all the questions you might have on system centering. My only concern would be that Bubba got hold of that 1975 gear and might have screwed it up sometime in the past.

http://jimshea.corvettefaq.com/wp-co...v28jl20091.pdf

Jim

 

You need to take a couple of steps back. While you have the box out is the time to ensure it is properly adjusted because it's the reason for what you should be trying to achieve here.

The box is built with a high point cut into the sector gear so that as you turn the box from one end to the other you feel a tightness as you go through the centre. It is designed this way because we do most of our driving going straight ahead and this makes the wheel want to stay there.

There are only two adjustments on the box. You back the sector adjuster out and put an inch lb torque wrench on the steering shaft. It should take about 5-8 inch lbs to turn the shaft. If you are less than that tighten the big nut on the steering shaft end of the box until you have it. Now tighten the sector adjuster until you get a reading that is about 4 inch lbs higher as you turn the box through the centre than whatever you had without the sector.

Now turn the shaft end to end counting the turns. Turn the shaft back halfway by count. You will feel the high point and will be in the middle of it. Don't sweat worrying if you might be one spline off) With the box in this position install your steering shaft so that your steering wheel spokes are centred as they would be going straight down the road.

Now attach the pitman arm. It is master splined and will only go one way.

Now your wheels may or may not be pointed straight ahead with the steering wheel in the straight ahead position. They could be off to either side. The correction for this is done at the alignment shop. When they set toe-in they put the steering wheel in the straight ahead position (in the high spot) and use the tie rod sleeves to bring the toe in to where it should be with steering wheel straight ahead (on the high spot on the box).

Steve g

 

Jim,
Thank you for the link, this is exactly what I was looking for!
Looks like my lower coupling was off by a tooth and the box now appears to be centered (turn wise) from left to right with the wheel being straight at dead center.

Thanks for everyone's input!
Elm