Saginaw Power Steering Box Questions

[OldSub]

A while back I bought a Saginaw power steering box at a swap meet that I thought was the right one for the kits that use a pickup steering box to put power steering on a '47 to '54 Chevy pickup.

I got to looking at it today and discovered its a little different than I needed.

The casting number (7802644) appears to check out as the right box and it is a front steer box that mounts outside the frame, but the output shaft is different and does not match the fully splined pitman arm for the correct application.

Instead of being splined all the way around the shaft with a threaded extension for the nut to hold the pitman in place, this one is splined only half way around the shaft and has a groove perpendicular to the splines for a lock bolt or something similar.

So here are my questions:

1) Any idea what this box is off of?

2) Any idea where I'd find a pitman that would work with this box?

3) I have another front steer Saginaw box that mounts inside the frame AND if the picture on RockAuto is correct, the right output shaft ('76 Cadillac DeVille).  Can I simply swap the output shafts?

It looks like the rebuild kit is much cheaper than buying another box and if its as simple as rebuilding and swapping the output shafts I'll just go that way...

I don't know the proper way to describe the output shaft, so here is a picture of the box I bought at the swap meet.



Thanks for any help you can offer!

[enjenjo]

You have a 4x4 truck box. The pitman arm uses a pinch bolt to hold it in place. As far as the Caddy shaft fitting, maybe, maybe not. If they are both variable ratio boxes, or both standard boxes, it will fit. But you can't mix a variable ratio pitman shaft with a standard ball nut, and vise versa.

Caution, unless you know what you are doing, don't remove the ball nut from the box, it is a bear to get back together. Removing the pitman shaft is no big deal.

[OldSub]

Thanks Frank!

If I knew what I was doing I probably would not have bought the wrong box in the first place.

Is there an easy way to determine if these boxes are variable ratio?

I'm assuming the pitman shaft is different because the pitman arms require different geometry and therefore finding a 4x4 pitman won't solve my problem.  Could that assumption be wrong?

[wayne petty]

just to add in....

one of the three possible boxes that could be... with the clamp type pitman shaft may have metric tube threads...

so you might want to try some fittings in if first...   may help.. may hurt...



napa   Part:    NSP 88278075
# Steering gear Box Mounting Holes : 4
# Steering Gear Box Turns : 3 3/8 - 3 1/2
Power Steering Gear Box Line Thread Size : M18 X 1.5; M16 X 1.5
Steering Gear Box Input Shaft Diameter : 3/4"
Steering Gear Box Output Shaft Diameter : 1 1/4"


~~~~~~~~~

Part:    NSP 88278053

# Steering gear Box Mounting Holes : 4
# Steering Gear Box Turns : 3 1/4 - 4 1/4
Power Steering Gear Box Line Thread Size : 11/16 X 18; 5/8 X 18
Steering Gear Box Input Shaft Diameter : 13/16"
Steering Gear Box Output Shaft Diameter : 1 1/4"

~~~~~~~~~~~~

Part:    NSP 88278064

# Steering gear Box Mounting Holes : 4
# Steering Gear Box Turns : 3 3/8 - 3 5/8
Power Steering Gear Box Line Thread Size : 11/16 X 18; 5/8 X 18
Steering Gear Box Input Shaft Diameter : 3/4"
Steering Gear Box Output Shaft Diameter : 1 1/4"

i know this won't help much...

[OldSub]

Wayne the combination of input shaft size and fittings does uniquely identify the box.  That at least allows me to sell it to someone else knowing what it is...

Thanks!

[enjenjo]

I'm assuming the pitman shaft is different because the pitman arms require different geometry and therefore finding a 4x4 pitman won't solve my problem. Could that assumption be wrong?

In it's original configuration, the pitman arm points to the left, straight out to the side, and the box is mounted to the outside of the frame just behind the front spring hanger. I don't know if that helps you or not.

If you drop the Caddy pitman shaft in, and it will turn from lock to lock without binding, it will work fine. If it binds part way through the travel, it's for the other type of box.

[wayne petty]

just in case you decide to open it...

here are a few articles with pictures so you can get an idea of what to do...

http://www.fourwheeler.com/techarticles/drivetrain/129_0801_saginaw_steering_box_rebuild/index.html

http://www.popularhotrodding.com/tech/0811phr_1968_chevy_chevelle_cpp_saginaw_600_steering_box/index.html

http://www.carcraft.com/techarticles/ccrp_0901_gm_steering_box_upgrade/index.html

http://www.off-roadweb.com/tech/0501or_4wd_steering_box/index.html

hopefully these will increase everybodys knowledge of steering boxes.


oh.. and here is a picture of the differences between the normal ratio and variable ratio pitman shafts

http://www.carcraft.com/techarticles/ccrp_0901_gm_steering_box_upgrade/photo_14.html


here is one more article..

about quick ratio steering boxes...
you only get one chance to read the article without dumping your cookies..
http://www.hemmings.com/mus/stories/2007/09/01/hmn_feature21.html

[OldSub]

hopefully these will increase everybodys knowledge of steering boxes.

Good reading!  I now know a lot more about these things than I did.

Short story is what Frank said, Pitman shaft is probably easy to remove/replace.  The rest of it gets much more difficult....

I'm in the mock up stage on this project and will probably rob the box off the Cadillac just because that's the fastest way to get there.  While it may not steer right if its the wrong combination of parts, it will let me keep going with building mounts.

Thanks!

[wayne petty]

i do believe that almost every other box will have the mounting bolts on the left side of the case...

that box should have them on the right as it bolts to the outside of the frame instead of the inside...

and the outside the frame boxes are hard to get ... less trucks than other  models made...

[jaybee]

Good info on the steering boxes, Wayne.  And getting a little harder to come by since on a lot of message boards the attitude is "why would you mess around with that old thing when you can send CPP a few hundred dollars?"  Seems kinda backwards to me.

[OldSub]

The local steering box rebuilder actually calls the 4x4 box I have 'rare' so it may have some value.  Today I'd cheerfully swap it for the 2wd version.

If I pull the Caddy box it will be to swap pitman shafts.  I already know it mounts inside the frame instead of outside.

[wayne petty]

one last link....

http://chevelles.com/techref/ftecref29.html

this is where the car craft link came from....

the url as in the text of the story and easily missed

[wayne petty]

thanks for the complements  

this is the actual link that shows how many degrees... it is on the other link  but  a few steps down..

http://www.chevelles.com/techref/shea_3.html


oops.. misposted this...

it shows the chart that has the torsion bar diameter.. and the amount of turning angle possible stop to stop in the various gm steering boxes...

a good chart to take with one when junk yarding... for steering boxes..

[jaybee]

Are replacement torsion bars available?  The biggest knock on these boxes for some applications seems to be that they're over-assisted.  High effort boxes are hard to find in the boneyards, but if parts are available for a torsion bar swap it could be a good option.

[wayne petty]

upon researching ... that list was assembled with data from lee manufacturing.. pendalton street sun valley...   between lankershim blvd.. and san fernando road just north of interstate 5...

one thing.. if any body ever makes a trip there.. in person...

at the san fernando road end of pendalton st... is APEX electronics... a giant surplus store...  it takes at least 2 hours to go through... stuff is stacked to almost to the ceiling.. 12 feet or so...


back to the torsion bars....  stiffer bars as i under stand increase road feel...

one of the links i posted had an article on rebuilding a gm box... and it showed how to change the torsion bar...