Steering Box Ratios (from Dan Jones,


 Here's the info I promised on steering box codes. The chart was taken

 from the March 1993 issue of Mustang & Fords ("Steering Steady").

 I've also included some of my steering notes that may be of interest.


                                          Dan Jones

                      Ford Steering Box Codes


 Long Shaft Boxes (HCC & HCA Prefix):

 Application                  Tag Code  Type     Ratio   Turns

 -----------                  --------  ----     -----   -----

 65-66 Mustang                HCC AW    Power    16:1    3 3/4

                              HCC AX    Manual   16:1    3 3/4 *

                              HCC AT    Manual   19.9:1  4 5/8

 65-66 Comet and Fairlane     HCA BZ    Power    16:1    3 3/4

                              HCA CA    Manual   22:1    6

 65-66 Falcon                 HCA BY    Power    16:1    3 3/4

                              HCA CA    Manual   22:1    6

 Short Shaft Boxes (SMA & SMB Prefix):

 Application                  Tag Code  Type     Ratio   Turns

 -----------                  --------  ----     -----   -----

 67-68 Montego and Fairlane   SMAB      Power    16:1    3 3/4

                              SMAC      Manual   22:1    6

 67-68 Falcon                 SMAF      Manual   16:1    3 3/4

 67 Mustang                   SMBA      Manual   19.9:1  4 5/8

 67-68 Mustang                SMBB      Manual   16:1    3 3/4 *

 67 Mustang                   SMBC      Manual   19.9:1  4 5/8

 67-70 Mustang and Cougar     SMBD      Manual   19.9:1  4 5/8

 67 Mustang and Cougar        SMBE      Manual   16:1    3 3/4 *

 68 Mustang and Cougar        SMBF      Manual   16:1    3 3/4 *

 69-70 Mustang and Cougar     SMBF      Manual   16:1    3 3/4

 68-70 Mustang and Cougar     SMBK      Power    16:1    3 3/4

                              SMBK      Manual   16:1    3 3/4 *



 - * 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),


 - 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.

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