Power Steering Manual Steering box

[Must1969 10]

:chris:I could not find a thread for this question so please direct me to it if you know where it is. I have a 1969 mustang with manual steering, i have bought a used complete OEM set up to switch it to power steering, Pump/center link, ram ect. The only part that I was not given was a different gear box. Any help would be great.

Edited March 3, 2011 by Must1969

[68stang289 26]

I switched to the power steering gear box when I did my swap on my 70. I believe you will need to get the power steering gear box because of the shaft that fits into the power steering style pitman arm. I'm pretty sure the p/s style pitman arm shaft is 1 1/8", but I could be wrong about that. I also went with a quicker ratio p/s gear box (16:1 vs. 19:1 I believe are the two options) since I was upgrading anyways and the price difference wasn't that much.

[LindenBruce 27]

Both manual and power have the same sector shaft diameter of 1 1/8" as long as they are both 67ish or newer. I can't remember on the exact year split. The only difference is the ratio between the two. Bruce

[Must1969 10]

Does the ratio make a big difference? I guess it does or they would have made them all the same ratio any one every use a manual box in a power steering set up?

Edited March 2, 2011 by Must1969

[Jayru 17]

Does the ratio make a big difference? I guess it does or they would have made them all the same ratio any one every use a manual box in a power steering set up?

 

Could be the quicker ratio MS box could cause violent oversteer with a power assembly because of the lousy stock PS setup? I've always heard they're oversensitive. The longer ratio might slow down/pad some of the sensitivity.

[Must1969 10]

So it looks like for safety reasons I need to get a power steering box.

[BuckeyeDemon 211]

i'm confused. i thought all power steering cars came with the 16:1 ratio.

 

in general people seem to want the 16:1 ratio for faster response (i.e. you don't need to turn the wheel as much to change lanes). the drawback is more steering effort in a non-power assisted car.

[Jayru 17]

in general people seem to want the 16:1 ratio for faster response (i.e. you don't need to turn the wheel as much to change lanes). the drawback is more steering effort in a non-power assisted car.

 

I'd think it's the opposite. You want the wheel to turn more (with less turning of the steering wheel) for MS cars. That would equal less effort. More effort would come with the longer ratio box (turning the steering wheel more to have the actual wheel turn the same distance as the quicker 16:1 rack.

[Brasil 10]

stay with your manual box....and ad the right pitman arm ( for Power steering ) to your gear box.... the 16 : 1 works perfect with the power steering !

 

Hope that helps

 

Greetings from Germany

Juergen

[BuckeyeDemon 211]

I'd think it's the opposite. You want the wheel to turn more (with less turning of the steering wheel) for MS cars. That would equal less effort. More effort would come with the longer ratio box (turning the steering wheel more to have the actual wheel turn the same distance as the quicker 16:1 rack.

 

when i wrote "wheel" i was referring to the steering wheel.

 

my 69 came with manual steering. it had the 19:1 box and was about 4.5 turns lock to lock. i just changed to the 16:1 box which is about 3.5 turns. less steering wheel action to change lanes.

 

Brasil, your comment confuses me. you say stay with the manual box and then you say 16:1.

[Jayru 17]

Interesting, my car is manual steering and I have a 16:1 box. I didn't think manual cars came with the slower ratio 19:1

[BuckeyeDemon 211]

manual cars had the 19:1 ratio because it made it easier to turn the steering wheel since it didn't have power assistance (at the cost of slower steering).

 

i would guess that's not the original steering box in your car. the effort required on a manual box put a lot more stress on them.

[Fordrevhead 29]

[ATTACH]8413[/ATTACH]

 

* indicates special high performance applications such as GT, Boss, Mach 1, etc.

- The steering boxes are identified by a tag attached to one of the steering box cover bolts. Use the number of turns to verify ratio.

- Early (64-70) Mustang power steering is of the non-integral, add-on assist type with a separate power cylinder and control valve. There is no difference between the manual and power steering boxes, except for ratios. The fast ratio manual steering box is the same as the power steering box.

- 1964-1970 Mustangs have two basic ratios:

1. 19.9:1 ratio, 4 5/8 turns lock-to-lock, used on all low performance manual steering cars.

2. 16:1 ratio, 3 3/4, used on all cars with power steering and on manual steering high performance cars (Shelbys, Bosses, GTs, Mach 1s, etc), optional?

- 1964-1970 Mustangs have two shaft styles:

1. 1964 to early 1967 boxes are the long shaft style where the box and steering shaft form one unit. There is no coupler, the shaft is one piece from the box to the steering wheel.

2. Late 1967 through 1970 are the short shaft style. There is a couple between the box and the steering shaft. This change was made to meet Federal Motor Vehicle Safety Standards (FMVSS) which required a collapsible steering column. Sector shafts were either 1" or 1 1/8". There are four different '67-'70 short worms used (2 ratios, 2 sector shaft diameters).

- The Ford steering box is internally (external housings are not shared) a GM Saginaw manual steering box. Since the Ford steering boxes use Saginaw internals, many GM parts interchange and some can provide performance upgrades.

- 1971-73 Mustangs with power steering use either a Saginaw or Ford integral power steering box.

- 1971-1973 manual boxes used a differently shaped external casting with a 1 1/8" sector and 24:1 ratio. There also used a slightly different frame mounting bolt pattern they won't interchange with 67-70 models.

- The 71-73 worm and rack assembly is identical to the 70-82 Corvette piece. The Corvette sector (GM P/N 7812838) and worm (GM P/N 7812942) will fit in 71-73 1 1/8" boxes if a new groove is scribed into the Ford pitman arm that corresponds with the index on the GM sector and if a Corvette coupler (GM P/N 7806391) is substituted for the Ford rag joint. Provides 16:1 ratio rather 24:1 ratio. Also the flat Ford-style sector shaft cover can be replaced with the 'Vette cover (GM P/N 7806748) which has an integral bushing that lends additional support to the sector shaft. The outer rim of the bushing support must be turned down to fit in the Ford box.

- In addition to using a fast ratio steering box, you can increase the steering rate by adding a Shelby quick steer kit (longer idler and pitman arms - What cars did these come from?).

 

Related Magazine Articles:

1. "Steering Steady", Mustang & Fords, March 1993

The article covers a Global West steering box rebuild. Side articles explain how a recirculating ball steering box operates and provide a method for adjusting your steering box preload. Also presented is a guide to identifying Ford steering box codes.

2. "Steerage Class", Mustang, February 1988

This article also covers a Global West steering box rebuild and provides a list of steering box part numbers that are still available (as of June 1987) from Ford. The article also lists some parts interchanges and upgrades using GM parts.

3. "Pressure Sensitive", Super Ford, September 1993

This article describes a simple way to increase power steering feel on vehicles equipped with Ford's non-integral power steering. The approach is to splice an adjustable valve in between the supply and return lines. Adjusting the valve varies the amount of boost, increasing steering feel.

Edited March 4, 2011 by Fordrevhead
formatting

[LindenBruce 27]

Excellent info FRH. Bruce

[Brasil 10]

@ buckeyedemon

 

what I wanted to say was.. if you have the 16 : 1 Box..( could be manual steering too - if you have a MACH 1 , Shelby.. or GT ) then you are fine with a added power steering... the 19: 1 Box will not work well with the powersteering...

 

I switched to 19: 1 because my car had a 16: 1 without Powersteering from the factory...( MACH 1 ) .. but with 7x15 and 235 /60 /15 had to drive around town here in Germany... now with the 19: 1 it is a lot easier..

 

Greetings Juergen

[BuckeyeDemon 211]

thanks brasil. did your mach have the competition handling package?

[Brasil 10]

...hmmm I had the 16:1 Steeringbox, but I am not sure if I have a special package

 

Greetings Juergen

[BuckeyeDemon 211]

now i'm curious as to how this worked!

 

my 69 mach was invoiced on 3/31/69. the date code on the steering box was 3/19/69 (less than two weeks before invoice). it's a 19:1 box. my car had manual steering. based on those build dates and the fact that my car hasn't been in service since 1983, makes me believe it was the original box.

 

perhaps someone at the factory could have installed the wrong steering box in my car?

 

or was the 16:1 box part of a special package beyond the mach 1? i can't image that all boss's and mach's received the 16:1 as a default on a manual steer car given the big block option.

 

i've seen references to heavy duty suspension's, competition handling options and wonder if that's where the option was. the front springs on my car were orange/yellow stripped indicating heavy duty.

 

just wondering.

 

 

[stangs-R-me 120]

"SMB-D" is definitely the 19.9:1 ratio manual box, interesting !!

 

I always thought the the 16:1 ratio "SMB-F" manual box was part of the "(GT) Handling Suspension" which was std. on all '69 Mach 1 & GT models.

 

But looking through the Mustang Recogition Guide, the only place I see the quicker ratio manual box mentioned is on the Boss 302. The "Illustrated Facts Book" also makes no mention of steering ratio on the Mach 1, GT, or Handing Suspension option.

 

Definitely a mystery.

 

Doug

[Brasil 10]

on my "old steering box " it says SMB-K and it is a 16:1 Ratio box. As far as I know, the MACH1 package also included the quick ratio steering box... because of the better handling...

 

Greetings

 

Juergen

[BuckeyeDemon 211]

brasil,

 

out of curiosity what is the date code on that steering tag and what is the date code on your door warranty tag?

[BuckeyeDemon 211]

i dug up the Ford Parts Book I have on CD.

 

for assembly 3504 (steering box), the Ford Catalog shows the following:

 

Brasil,

By the way that table reads, your manual steering car with a 16:1 ratio should be a code SMB-F. The SMB-K is shown as a 16:1 ratio box for a power steering car.

 

Perhaps ford ran out of the SMB-F boxes and put a SMB-K in your car.

 

i don't know where the mustang shop is getting their data from. others seems to have copied the same source data from somewhere.

 

stangersite has a table that looks old and seems to agree with the Ford Parts book.

 

i just have a hard time believing a big block mach or a Boss 429 would come standard with a 16:1 gear ratio. The Boss 302 was a different animal, set up for the track with a lighter motor.

[stangs-R-me 120]

SMB-K was the 16:1 Power Steering Box but also the service replacement for the SMB-F 16:1 box used on Manual Steering cars (per Ford Shop manual). Why the SMB-F existed at all really makes no sense to me.

 

Doug

[Brasil 10]

Perhaps on of the former owners did the "swap"..? My car seems to be a little "special" anyway... for example insted of a FMX Tranny My car has a C6.... and the Brakes in the rear are also something "special" ..the drums are 10" X 2 1/2" the linings also.. perhaps they are from a TORINO...or 66 Shelby..? Because 20 years ago the former owner had a 350 GT Sheby also..but rusty rusty... so he used some parts from the Shelby to get ready with the car I have right now...

 

Greetings from Germany

Juergen

[Brasil 10]

...another thing, I went throu all my books and catalog I have...but I couldn´t find some advise about the stock steering ratio of a MACH 1...so perhaps they came from the factory with M/S 19: 1 Gear Ratio...and the Upgrade to P/ S also included the 16: 1 BOX ???

 

Greetings Juergen