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I found this info on steering gear boxes. Looks like they are all the same, might be mistaken.


The Saginaw gearbox is a rotary-valve type unit using recirculating ball bearings. They are referred to as recirculated ball-type because they use the same ball bearings on both the worm gear and the sector gear to reduce friction within the housing. You will often see this gearbox referred to as an "800" or "605" unit. The only major difference between these two units is how the pitman shaft is held into the unit. An 800 unit has a four-bolt cover on the top of the unit (the end of the shaft opposite the pitman arm spline). The 605 units use a single snap ring that holds a round cover into the top of the housing. GM also used two gearboxes, depending on the weight and size of the model. Station wagons, full-size cars and large front-wheel-drive cars used a heavy-duty gearbox usually identified by GM part number 5687962. These units had a 3.5-inch piston diameter, and the pitman shaft will turn anywhere from 3.5 to four turns between fully locked left and fully locked right. These units were rated at a 17.5:1 steering ratio. Mid-size and smaller models used a steering box tagged 5691676, and these units used a 3-inch piston. The travel on the smaller-piston unit was three to 3.5 turns lock to lock. The mid-size gearboxes were rated at a 14.4:1 steering ratio. Both the 3.5-inch and the 3-inch-bore gearboxes have a .813-inch input shaft diameter, and most will have 31 splines on the input shaft. You can substitute between both of these units. Aside from the mounting bolt pattern (most are 4-bolt mount but there are two different three-bolt mounts, as well), these units are all interchangeable. The more responsive 14.4:1 ratio gearboxes replaced the earlier 17.5:1 ratio boxes in most models by 1973. This is a good thing to remember when you begin your search for a replacement.


You can locate one of the basic Saginaw "800" series power steering boxes in one of these vehicles:

1964-'76 AMC
1961-'76 Cadillac, including
1963-'76 Eldorado
1964-'76 Buick and Pontiac full-size cars and Riviera
1973-'76 Regal
1975-'76 Skyhawk, Seville, Monza and Starfire
1965-'76 Chevrolet full-size cars
1967-'76 Camaro and 1968-'76 Nova
1964-'76 Chevelle, Cutlass, GTO, Grand Prix, Lemans, Ventura and Tempest
1971-'76 Vega and 1975 Pontiac Astre
1960-'76 Oldsmobile full-size cars including 1966-'76 Tornado
1971-'76 Jeep Cherokee, Wagoneer, Gladiator and J-series pickups
1972-'75 International Scout and Traveler

Many enthusiasts have also found that an easy way to upgrade the handling on your car is to convert to a Saginaw quick-ratio power-steering box. These were original equipment on some mid-size models, and they can be transplanted into most other GM vehicles, if you can locate one from your local pick-a-part. These gearboxes will improve the steering and handling for your car with a more responsive lower gear ratio and also reduce the steering wheel travel to 2.25 to three turns.

The 1969-'76 Camaros as well as 1964-'76 Chevelles, Malibus and Monte Carlos also used an optional quick ratio 12.7:1 unit, which will interchange with the higher ratio gearboxes. These are very popular units because they are an easy bolt-in performance conversion. The 1982-'96 S-10 pickups used a 14.0:1 ratio "605" series gearbox, which will interchange into earlier vehicles with some modification. Another option is to use late-model G or F Body units. They were original equipment on 1983-'88 Monte Carlo, 1983-'84 Hurst Olds, 1985-'87 Olds 442, and 1984-'87 Buick Grand National or T-Type. They are also 12.7:1 units and a little more difficult to find, but can be identified by a "YA" marking on the end cap (opposite where the steering column attaches) or by searching for cars with the F41 or Z65 suspension package. All of the Monte Carlo SS cars had these options. These units will reduce steering wheel revolutions from lock to lock down to 2.25 to 2.75 turns.

An important thing to remember when interchanging Saginaw gearboxes is to use your original pitman arm and idler arm if possible, to maintain the proper steering geometry. Different body styles have different length idler and pitman arms; for example, the F body arms are longer than those in an A or G body and could cause alignment and front-end clearance problems if used in different body styles. When interchanging between earlier and later GM gearboxes, you will notice the power steering hose fittings are not the same. Later fittings are metric and incorporate an O-ring, whereas all Sixties and most early Seventies units used the standard inverted-flare fittings. Auto parts stores sell standard thread to metric thread adapters in several different sizes that allow you to use your original hoses with the later-design metric gearboxes. The rag joint or steering gear coupler may also have to be changed. These can be obtained with the gearbox when being pulled from the donor car, or new ones are still available from the GM dealerships. The coupler off a 1977-and-up Chevy pickup (GM part number 7826542) works just fine to adapt the early-style steering shaft to the later model gearbox. Rag joints are also available from Lares Corporation, which can assist you with interchangeability questions and the purchase of freshly remanufactured power steering components as well.

Lares Corporation 1-800-334-5749

Finding a replacement gearbox for your General Motors car can be very easy because of the abundance of original units available that will readily interchange. Completing an upgrade to a quick ratio steering gearbox can also give your ride some additional handling and make a classic drive like a newer model.


AGR Performance

Classic Industries

Classic Performance Products

Firm Feel Suspension

Flaming River

K.A.R. Mustang

Original Parts Group

Power Steering Services Inc.

Superior Mustang Parts

12.7:1 quick ratio installed on the “SS” Monte Carlo, Trans Am, and Firebirds of the ’80′s

GM/Saginaw quick-ratio steering box donor car cheat sheet

Late Model 12.7:1 quick-ratio gearbox
ID markings YA, WS and HX
Line Thread Size: M18x1.5 and M16x1.5
Number of Mounting Holes: 3, (missing leg H-pattern)
Input Shaft Diameter: ¾-inch
Output Shaft Diameter: 1 ¼-inch
Number of Turns Lock to Lock: 2 ½ - 3

1984-'88 Monte Carlo/Malibu with Z65 suspension
1983-'88 Malibu, El Camino
1982-'92 Camaro except FE1 soft ride suspension
1984-'87 Regal with FE2 or FE3 sport suspension
1983-'84 Hurst/Olds
1985-'87 Cutlass with 5.0 (VIN code 9)
1982-'85 Trans Am
1986-'92 Firebird except FE1 suspension
1986-'87 Grand Prix with FE2 touring or F41 heavy duty suspension


Pre-'76 12.7:1 quick-ratio gearbox
Line Thread Size: 11/16 x 18 and 5/8 x 18
Number of Mounting Holes: 4, (H-pattern)
Input Shaft Diameter: 13/16-inch
Output Shaft Diameter: 1 ¼-inch
Number of Turns Lock to Lock: 2 ½ - 3

1967-'76 Camaro, Firebird
1970-'76 Monte Carlo/Malibu
1964-'76 Chevelle


1977-'79 12.7:1 quick-ratio gearbox
Line Thread Size: 11/16 x 18 and 5/8 x 18, Number of Mounting Holes: 3, (missing leg H-pattern), Input Shaft Diameter: ¾-inch, Output Shaft Diameter: 1 ¼-inch
Number of Turns Lock to Lock: 2 ½- 3

1977-'79 Camaro, Firebird-1977-'79 Monte Carlo, Malibu-1977-'79 Chevelle

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  • 2 years later...

hello, i have a 1967 buick riviera and am changing out the original saginaw steering gear 4 .25 turn ltl to a 1964 to 76 4 hole mount saginaw, i believe it is 2.5 ltl not sure, does anyone know the correct number of turns for this 64-76 saginaw, its not here yet i know it will bolt up but does anyone know if i will lose radius in turning, what will be the pros and cons, it will be here in a day thank u anyone responding.

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When you get the new box, compare it to the old one. The original is an 808 box with a 3.5" piston; that's what GM used on their fullsize cars.  The overwhelming majority of GM quick ratio boxes available are the smaller 600 series box with a 3" piston that was used on lighter cars.  The two are interchangeable (that is, a 600 box is a drop-in replacement for an 808 box) but they are not identical.  There's some debate as to whether the 600 box will work on the heavier Riviera, but you should be aware that it is not the box that the car was made with.


Number of turns lock-to-lock doesn't tell you anything by itself (it's actually a fairly worthless number), as that is affected by both gear ratio and internal stops.  It is those stops which may compromise turning radius.  Again, compare the new box to the old one.  Compare the rotation of the pitman shaft on the two boxes -- that's the only way to know.

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PWB & diaztec,




  I have already done ALL the research needed for our BIG CARS.  All the guess work has been done & taken already.  Why not take advantage of my love for these cars. They are a fast ratio 2.5 turns lock-lock & in our RIV's. & are a 12.5-1 ratio. 





MY rebuilt boxes are about 1/2 the cost or less of some of the bigger company's steering boxes.



IF you are willing to take the chance I know you'll be happy.  So FAR there have been no COMPLAINTS.

They are $450.00 plus shipping costs.


Tom T.


P.S.- I have a '65 RIV. fast ratio box at 3 turns lock-lock.  IF anyone is interested for $350.00 plus shipping costs & a return core.

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I recently installed one of Tom T's boxes. Even though I have only operated it on my backyard buddy lift, I can tell you this; these wheels turn MUCH faster than before.  I most assuredly did not have a fast ratio steering box as original.

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                   If Tom's boxes have the correct stops, I would go with them. More often than not when you buy somebody's

quick ratio box your car needs 40 acres to make a u-turn because the turning radius is way off.

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Winston,  (and ANYONE else thinking about it)


  As I stated in my reply above "My boxes DO NOT compromise turning radius & is EXACTLY the same as  stock because it starts out as an "808" steering box to begin with, not some adaptation of some other model steering box. It's a bolt-in. Noting else needed EXCEPT if your rag joint needs replacing.


Tom T.

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1 hour ago, telriv said:

Winston,  (and ANYONE else thinking about it)


  As I stated in my reply above "My boxes DO NOT compromise turning radius & is EXACTLY the same as  stock because it starts out as an "808" steering box to begin with, not some adaptation of some other model steering box. It's a bolt-in. Noting else needed EXCEPT if your rag joint needs replacing.


Tom T.

Tom, might you have a YouTube video(s) showing the installation of your steering boxes? I am considering getting one of yours. Can I replace this by myself or is help recommended?

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Again to ALL,


   The chassis manual is your best friend when working on ANY vehicle.  It's ALL explained probably better than I can.  The ONLY caution I can give is when your installing the box OR anyone else's boxes. You have to remember this a FULL SIZE car box & it's heavy. Coming out is easier than installing so it would be advisable to have help because as I stated this steering box is HEAVY.  AND it's not because it's heavy, BUT ALSO that your in tight quarters & it's awkward trying to move around while your trying to hold the box in place & getting things lined up will be just about impossible. Unless your on a lift which many of you I will assume will not. Still it's certainly easier to do with help.  Next to make things neater you could clamp both hoses with a pair of needle nose vise grips to help with the oil that will come out of the hoses.  Just don't clamp them too tight as all your trying to do is keep oil from dripping all over you & making it more unpleasant to work.

   The ONLY other thing I can say is get a "crows foot"  (11/16" & 5/8") that has an end like a line wrench that you can put a long extension on

to break the lines loose. After installation of the box make sure the lines are tight, again the using the crows foot to now tighten the lines.  You could go to one of the auto stores that lend out tools as most I'm sure do not have a 1 5/16" socket or a pit-man arm puller.

You will see a flat on the input shaft of the steering box & a flat on the coupler attached to the rag joint. With white-out or some other kind of marker (not something really wide other than a line) put a line in the middle of both flats.

Get the steering wheel in a position where you can see the flat from below & the flat on the input shaft of the steering box. Use something to hold the steering wheel in that position OR whatever position you feel nec. for you to see the lines your going to be able to see from below.  What this does is give you a reference to line up the two lines & the middle of both. This helps to get the twp pieces to line up exactly.  IF the input shaft won't slide into the rag joint fairly easily your probably not lined up.   What you DON'T want to do is force them together.  IF you say the heck with it & continue number one it will be difficult to remove the improperly mated parts, But it may also be impossible to install the clamping bolt.


                                            Torque Specs


Lower coupler (rag joint) pinch bolt                20-35 ft. lbs.

Steering box to frame                                        60-75 ft. lbs.

Pit-man arm nut                                                 90-110 ft. lbs.


Average time experienced                      3/4 - 1 hr.

      "          "         Novis- DYI                         2-3    hrs



Tom T.




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On 4/30/2019 at 2:22 PM, NC68Riviera said:

Tom, might you have a YouTube video(s) showing the installation of your steering boxes? I am considering getting one of yours. Can I replace this by myself or is help recommended?

I put one of Double T’s newly rebuilt steering box in my 63. Everything Tom says is True with a capital T. I did need help guiding the steering box into the rag joint. Other than that I took out the steering box and reinstalled myself. The steering box has really helped with steering, handling, and ride. I would suggest you have a tube/line crows foot with extension to tighten the power steering lines. I highly recommend the product.


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I've replaced these boxes by myself with a lift and flat on my back.  It's a PITA either way, as you will end up trying to hold it steady with one hand while inserting a bolt with the other.  I suppose if you're really inventive you could make a cradle and sit it on a jack, but you could probably have it in place in less time.  The best advice I can give is make sure you have a bolt right there and brush up on your profanity.  And watch out for spewing fluid.  As Tom says, clamp those hoses to save yourself from an unpleasant shower.

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I've used a floor jack to hold it, and pieces of 2x4 to make a cradle for it. Worked ok. I like using a piece of pipe on a breaker bar to make it easier to get the bolts loose. I've only done it about 3 or 4 times, every time was wrestling a bear.

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