71-73 steering box on older stang

It might work if you grafted on the left side portion of the frame rail from a 71-73. You'd need to work on a drag link to fit the pitman arm and pay attention to the steering geometry. It would not be a simple job.

The 71-73's used a Saginaw box, so if you could make it work, you could use a 12:1 high effort box from a Z28 or WS6 Trans Am. These are nice boxes with good steering feel. Or you could get a new box with the same specs.

pabear89, you're going through the same thought process I've been on for a while now... There have been a couple threads about this idea:

thread I started: http://forums.stangnet.com/showthread.php?s=&threadid=266687

posted by Sundance: http://forums.stangnet.com/showthread.php?s=&threadid=288954

The general concensus on retrofitting the '71-'73 box is that its just too big to fit in the space available in earlier cars (especially if using headers). That said, it appears no one has actually attempted the swap (to my knowledge).

This might be a good opportunity for me to share my research on the subject of improving the stock power steering. Here's some stuff to consider:

1) Flaming River box: better tolerances than stock (even rebuilt), same 16:1 ratio, uses needle bearings which doesn't wear as much as quickly. Cost under $400. That said, the stock box has worked just fine for over 30 years (at least mine has anyway), and its the least of my problems in terms of slop.

2) Pro-motorsports bump steer corrector kit: from their website: " The Bump Steer Kit quickens the steering ratio, by approximately 1/2 turn, and reduces the Ackermann angle (great for additional cornering speed). Recommended for competition use only due to greatly enhanced steering response and some increase in steering effort. Used stock inner and outer tie rods." Cost $240. Sounds good to me. https://www.pro-motorsports.com/store/products.asp?id=8

3) Cobra Automotive idler arm roller bearing kit: I've heard really good things about this... I think cost is around $60 (just for the roller bearing kit)http://cobraautomotive.com/Handling.htm

4) poly rag joint... anything that will add a bit of sensitivity back is good, right?

5) Shelby quick steer kit (idler and pitman combo): rumor is that this is a good mod, but its supposedly not an option for power steering cars (something about clearance/travel issues), but I don't have the specifics. Cost under $120.

6) adjustable fluid pressure valve: this is a mod I first read about in the early '90s in Super Ford magazine. It involves putting an adjustable valve in the ps supply/return lines to control the amount of pressure getting to the ps control valve. This supposedly adds a bit of feel and sensitivity back to the system, and takes away that "over powered" feel of the stock ps. I'm planning on doing this one the moment I get the chance.

7) Mitsubishi Sigma steering box conversion: I don't have hardly any info on this yet, other than it was mentioned on a New Zealand website. I've emailed the guy who came up with it, and he says he'll be emailing me the details after the new year. I'll post a thread when I get the info.

That's all I can think of at the moment... hope it helps.

i just bought a 66 t-bird and noticed that it has the internal power steering box(better road feel).has anyone ever tried using one of these?

The biggest problem with the Bendix style linkage-assist power steering system is the slop that is designed in. The pitman arm has to physically move the ball stud in order to operate the valve before the steering linkage even begins to move. That big steering wheel movement and lack of on-center feel before anything happens is a design feature. Toss in all the leaks and you have a system that everyone loves to hate.

Rebuilding/replacing the valve, installing a new steering box, quickening the steering, and/or replacing the entire linkage will help eliminate the play caused by normal wear, but will never, ever eliminate that built in movement that has to occur before the assist kicks in.

As far as the T-bird box, while it may be better, I don't think there are any fast ratio, high-effort boxes available, so your steering would probably end up as soft and overboosted as it was on the 'bird. If any of you figure out a way to install the excellent Saginaw box, I'd love to see it.

Anybody ever think of installing a Saginaw 605 box like they do in Tri-five Chevy's? http://www.carnut.com/specs/steering/pwr605.html

i agree that the t-bird box is probably a slow ratio,too much
power assist box(don't know haven't driven it yet) but i think
the assist could be lessened.it may even be built by saginaw?????
it would get rid of the fork-lift design steering though...

6T6coupe said:

The biggest problem with the Bendix style linkage-assist power steering system is the slop that is designed in. The pitman arm has to physically move the ball stud in order to operate the valve before the steering linkage even begins to move. That big steering wheel movement and lack of on-center feel before anything happens is a design feature. Toss in all the leaks and you have a system that everyone loves to hate.

Rebuilding/replacing the valve, installing a new steering box, quickening the steering, and/or replacing the entire linkage will help eliminate the play caused by normal wear, but will never, ever eliminate that built in movement that has to occur before the assist kicks in.

Click to expand...

I understand the system isn't ideal, but ya know, I never thought it was all that bad. I've said this before, and I'll say it again: I've driven cars with integral boxes (including the ever prevalent saginaw), and some have been better in terms of feel and response compared to my stock system, but some have also been worse.

The entire time I drove my Mach daily (my only car for the better part of 6 years), I never found the steering to be troublesome or so vague that I couldn't easily keep the car in its own lane, or point it where I needed to. I also never suffered the tremendous amounts of bump steer I hear everyone complain about (and I was driving the car in Tampa, and anyone who has driven there knows how bad the roads can be, and the damn train tracks every 1/2 mile).

Personally, I just want a system that is more responsive and has more feel, 'cause for the most part it seems to function pretty well otherwise.

And while I like the idea of a rack&pinion conversion, there are some serious (to me) drawbacks. Most of all, the loss of turning radius. This may not be a big deal to many, but if you drive your car in a city like Seattle, or SF, or Chicago, and you have to negotiate tight parking lots and parallel park regularly, then you know you can't afford to lose any turning radius.

Another of my big concerns about the rack&pinion conversion is that most (if not all) are proprietary systems. This means if the rack fails, breaks, gets clobbered by something, and has to be replaced, then you have to source another one from TCP, or Flaming River, or Rod&Custom, or whoever. Admittedly there are probably exceptions (I think Randall's rack is a production piece, and he has a cure for the loss of turning radius), but still, if you actually drive your car, and the rack gets fragged in the middle of Nowhere USA, you're in a tough spot to get it repaired. Stock steering parts are available at most regular auto parts stores (especially NAPA), and any two-bit mediocre mechanic (like me) can put it together.

what vehicles use the 605 box?

pabear89, I've been looking into all of our options, and most of them are a bit pricey, but may be worth it in the end, like the Pro-motorsports bump steer corrector kit (as it appears to be the only one designed not only to lower the tie rod end, but also moves it forward, increasing the functional turning ratio). But some of the stuff is darn cheap, like the poly rag joint and the adjustable fluid control valve, if not reasonable, like the roller bearing kit.

Also, one other thing I've come across in my research is the importance of maximizing the performance of the stock components by maintaining proper adjustment, like the main offender, the ball stud. In fact, here is a great thread from a vintage Corvette forum about ball stud movement and adjustment (early Corvettes used the same Bendix ps system design as our Mustangs):
http://forums.corvetteforum.com/zerothread?id=479912

Anyway, keep up the good fight, and post when you find anything new. I'll do the same. And maybe between a couple of us we can really find some viable options and improvements.

wow!i didn't know vettes used the "forklift"steering
never driven one though.is the saginaw box front or
rear steer?