Stock '76 or 4x4x2 power steering box?

[plothead]

Team
I've been through a few threads about this same subject, but I'm still hoping for a couple of opinions.

Facts:

• 26 years ago, I converted to power steering by combining 2 donor PS boxes to make the 4x4x2 PS box. Loved it, worked great.
• About a year later (2001), I started a full rebuild and removed the 4x4x2 box with the intention of installing a stock '76 steering box. Welded up the 4x4x2 holes and installed the frame plate and internal braces for a stock PS box.
• '76 box is in original condition, no rebuild/reseal/etc. was done.
• Life changed, ran out of money, stopped rebuild.
• 2025 life changed, better spot financially to do this rebuild/restomod mostly right.

About the Bronco:

• 31" tires
• 99-100% street driving only
• 1" suspension lift
• Saginaw PS pump

After reviewing the posts on this site, I'm wondering what course of action I should take.
I see my three options are:

1. Install '76 box as is and then rebuild later if needed;
2. Rebuild '76 box and install it (heard it's medium hard/technical, but I did successfully do the 4x4x2 rebuild in my parents' driveway);
3. Rework the reinforcement plate and braces to use the 4x4x2 box again

Which option do you all recommend I pursue, knowing it's a street driver with mild lift and mild tire sizes?
Other thoughts?

Thanks in advance,
CD

 

[plothead]

I should add that I was told it was a '76 PS box. It still has the tag on it.
Is there a way to confirm the year the box was built/from and the original PS box's turn ratio?
I liked the quick turn aspect of the 4x4x2, so that should be a factor in my decision moving forward.
Ty,
CD

 

[Viperwolf1]

Nothing wrong with an original box. They're good, strong units. For your intended use it should last forever.

A '76-'77 box should have a tag with the code SPA AU. The input shaft should turn about 4 1/4 turns. Same ratio as the Ford box. There is a casting date on the box, something like "7234". The 7 is the year, 1977. The 234 is the julian date.

Install it, try it, see if it works and doesn't leak. The rebuild is a little more complex than converting a Ford box.

 

[jamesroney]

I should add that I was told it was a '76 PS box. It still has the tag on it.
Is there a way to confirm the year the box was built/from and the original PS box's turn ratio?
I liked the quick turn aspect of the 4x4x2, so that should be a factor in my decision moving forward.
Ty,
CD

Here's my advice.

1. You did not "rebuild" a 4x4x2 steering box in your driveway. You swapped the worm and ball nut. It is required in order to reverse the direction of your 4x4x2 box. Don't conflate swapping parts with "rebuilding." Although some of the steering box companies are just parts swappers...the good ones actually perform a rebuild, including re-calibration of the spool control, new seals, new bearings. and careful "blue-printing" of all critical components.

2. You can confirm the date that your "76 box" left the foundry by the casting date code. Be mindful that the tag is easily moved. But if you have it...it's easy enough to just count turns. SIX is a lot more than FOUR. Since you seem to have it in your possession...clamp it into a vise. Steer it all the way to one side. Count the turns exactly to get to the other stop. Divide that number by 1/2. If the number is about 2...keep going. if the number is about 3...stop. Return your box to the exact center. measure the play of the pitman arm. You are looking for the amount of lash between the worm and sector. (Do NOT, under any circumstance...touch the adjusting bolt, or that 5/8 jamb nut. Others will tell you to adjust it. I'm telling you NOT YET!) Measure the lash. If it is loose, then stop. If you have a 4 turn Saginaw box that is not worn out, there is no reason not to run it. It won't get "better" by opening it up and dumping money into it.

3. The factory saginaw box is vastly superior to the 4x4x2 box in one aspect that no one mentions. The factory Bronco box has a slightly bigger angle of total steering ARC. That's right. The factory box lets you make a u-turn on your street. The 4x4x2 box will turn short. Same RATIO, but less ARC. It's maddening. It's not much, but it's there. Drives me bananas. Other than that...the 4x4x2 box is superior in all aspects.

4. The 4x4x2 (WCB) frame plate is an engineering marvel that has no business on a build. It is ONLY used when you are trying to sell a "bolt on" solution. Which means it is inferior to any proper installation. The 4x4x2 box can be bolted directly to the frame, and should be. That silly plate moves the rag joint into the apron, adds leverage to the mount. and I absolutely despise them. A properly bolted 4x4x2 box on an EB is equal to or superior to a Saginaw box.

5. The factory saginaw box is superior from a logistics and service perspective. The 13/16-36 input spline, and the 11/16 threaded input pressue nut are oddball, but "Early Bronco" So any shop can deal with it. Those Delphi conversions, Ford Boxes, and the IH box are built to the GM standard. So hoses, and couplings are "different."

@Viperwolf1 is giving some great advice above. A "good" Factory Saginaw box will outlive your Bronco.

 

[tirewater]

If you use the '76, it probably wouldn't hurt to replace the pitman shaft seal prior to installing the arm & filling with fluid.

I rebuilt my steering box - and used two rebuild kits as I munged up the teflon seals on the valve body when installing. I would agree with the sentiment above to avoid rebuilding unless you know it needs it.

To point out the obvious, be sure to test fully before hitting the streets.

 

[plothead]

Gang, this is great, thanks.
@jamesroney, you are right; I did some swapping around of parts rather than a full rebuild.
Thanks for the guide on how to test for lash (hopefully none) in the box.

It turns out that the box is a six-turn (tag is SPA Z), and I can't say that bothers me. I remember liking the 4x4x2, so if the 6 turn isn't for me, I can always go that route.
And the plate and inside-the-frame stiffeners I welded on were like the frame reinforcement kits that Tom's and others sell. I think it was from BC Broncos when they were still in CA. It should work for the factory box, IMO.

My follow-up question is now about the 6-turn box.

• Still worth putting in as-is and seeing how it goes, like @Viperwolf1 suggested?

Thanks for all the feedback.
CD

 

[lars]

Here's my advice.

1. You did not "rebuild" a 4x4x2 steering box in your driveway. You swapped the worm and ball nut. It is required in order to reverse the direction of your 4x4x2 box. Don't conflate swapping parts with "rebuilding." Although some of the steering box companies are just parts swappers...the good ones actually perform a rebuild, including re-calibration of the spool control, new seals, new bearings. and careful "blue-printing" of all critical components.

2. You can confirm the date that your "76 box" left the foundry by the casting date code. Be mindful that the tag is easily moved. But if you have it...it's easy enough to just count turns. SIX is a lot more than FOUR. Since you seem to have it in your possession...clamp it into a vise. Steer it all the way to one side. Count the turns exactly to get to the other stop. Divide that number by 1/2. If the number is about 2...keep going. if the number is about 3...stop. Return your box to the exact center. measure the play of the pitman arm. You are looking for the amount of lash between the worm and sector. (Do NOT, under any circumstance...touch the adjusting bolt, or that 5/8 jamb nut. Others will tell you to adjust it. I'm telling you NOT YET!) Measure the lash. If it is loose, then stop. If you have a 4 turn Saginaw box that is not worn out, there is no reason not to run it. It won't get "better" by opening it up and dumping money into it.

3. The factory saginaw box is vastly superior to the 4x4x2 box in one aspect that no one mentions. The factory Bronco box has a slightly bigger angle of total steering ARC. That's right. The factory box lets you make a u-turn on your street. The 4x4x2 box will turn short. Same RATIO, but less ARC. It's maddening. It's not much, but it's there. Drives me bananas. Other than that...the 4x4x2 box is superior in all aspects.

4. The 4x4x2 (WCB) frame plate is an engineering marvel that has no business on a build. It is ONLY used when you are trying to sell a "bolt on" solution. Which means it is inferior to any proper installation. The 4x4x2 box can be bolted directly to the frame, and should be. That silly plate moves the rag joint into the apron, adds leverage to the mount. and I absolutely despise them. A properly bolted 4x4x2 box on an EB is equal to or superior to a Saginaw box.

5. The factory saginaw box is superior from a logistics and service perspective. The 13/16-36 input spline, and the 11/16 threaded input pressue nut are oddball, but "Early Bronco" So any shop can deal with it. Those Delphi conversions, Ford Boxes, and the IH box are built to the GM standard. So hoses, and couplings are "different."

@Viperwolf1 is giving some great advice above. A "good" Factory Saginaw box will outlive your Bronco.

Great advice, @jamesroney!

I have something slightly oddball to add to your list. 28-ish years ago when I wanted to convert my box stock 70 to power steering my OCD prevented me from using the inside-the-frame rail F100 box. I was lucky to be able to source an intact 1977 power steering box from a long-forgotten supplier for a good price and used that instead.

Years later I had learned about the 4x4x2 option and at the same time heard about someone who split his factory 1977 box in two. I wasn't terribly concerned about doing that because by then I was already over wheeling mine that hard. But I also noticed (this is the important part) that people were starting to pay ridiculous prices for the factory 76/77 boxes. I pulled mine, put it on ebay and sold it for enough to buy everything for two complete 4x4x2 swaps plus parts for a third and have money left over. The first, swapped in but never rebuilt, is still soldiering on. Ok maybe I replaced the bottom seal, don't remember. Doesn't leak. But cue #3 in your list. Yup..

No idea what the market is like now. The hoarder in me is glad to have spares though.

 

[bigmuddy]

Great advice, @jamesroney!

I have something slightly oddball to add to your list. 28-ish years ago when I wanted to convert my box stock 70 to power steering my OCD prevented me from using the inside-the-frame rail F100 box. I was lucky to be able to source an intact 1977 power steering box from a long-forgotten supplier for a good price and used that instead.

Years later I had learned about the 4x4x2 option and at the same time heard about someone who split his factory 1977 box in two. I wasn't terribly concerned about doing that because by then I was already over wheeling mine that hard. But I also noticed (this is the important part) that people were starting to pay ridiculous prices for the factory 76/77 boxes. I pulled mine, put it on ebay and sold it for enough to buy everything for two complete 4x4x2 swaps plus parts for a third and have money left over. The first, swapped in but never rebuilt, is still soldiering on. Ok maybe I replaced the bottom seal, don't remember. Doesn't leak. But cue #3 in your list. Yup..

No idea what the market is like now. The hoarder in me is glad to have spares though.

As usual good points Lars!
Depending on location, the factory boxes have come down in price. I think this is primarily due to the prevalence of the aftermarket boxes being available. My .02

 

[lars]

I think I paid around $250 for my '77 box. Which seemed extravagant at the time. Sold it for almost 3X that amount. Insane, really.

 

[bigmuddy]

I think I paid around $250 for my '77 box. Which seemed extravagant at the time. Sold it for almost 3X that amount. Insane, really.

$250 is a great price for a new one or newly rebuilt one, even back then. They got up to $800 for a while for a good used one (4 turn)
Prices have come down depending on where you in the market.

I remember when you couldn't locate one.