Ford 9-Inch Width Chart (1957–1986): Axle Widths, Housing Ends & Bearings
Ford 9-inch axle widths are usually quoted flange to flange, wheel mounting surface to wheel mounting surface. Common widths are 57.25 in (1965–66 Mustang and 1957–59 Ranchero or wagon), 59.25 in (1967–70 Mustang), 61.25 in (1971–73 Mustang), 58 in (1966–77 Bronco) and 65.25 in (1973–86 big 9-inch). A bare housing is about 5 in narrower than these numbers.
Ford built the 9-inch from 1957 to 1986, and Wikipedia says the 8.8-inch replaced it. This page lists widths, housing ends, bearings and spline counts. Ford does not publish a consumer width chart, so the numbers come from parts retailers and aftermarket makers, and we point out where they disagree.
How to Measure a Ford 9-Inch Axle
There are two common measurements, and mixing them up is the usual source of fit problems. a Jalopy Journal thread shows owners using five different ways to measure the same axle.
- Axle flange to flange (wheel mounting surface to wheel mounting surface). The distance between the faces where the wheels bolt on. Charts quote this number.
- Housing flange to flange. The bare housing from one tube end face to the other, with no axles or brakes. A compilation of the common list says to subtract 5 in from the quoted width to get the bare housing length.
Do not measure from the brake drums. If the axle is already in a car, measure the wheel mounting faces. For other Ford axles, see our Ford rear axle width chart and Ford 8.8 rear end width chart.
Ford 9-Inch Width Chart
Axle widths follow the list published by JEGS and repeated by a 429-460.com forum compilation. The bare housing column subtracts 5 in, as that compilation advises. The forum poster who compiled the list was warned by another member that several of its source sites have inaccurate dimensions, and a few entries repeat with different values, so treat every row as a starting point and measure.
| Vehicle | Years | Axle width (flange to flange) | Bare housing (about) | Notes |
|---|---|---|---|---|
| Ranchero and station wagon | 1957–59 | 57.25 in | 52.25 in | Called the narrowest 9-inch housing |
| Falcon | 1964 | 58 in | 53 in | |
| Mustang | 1965–66 | 57.25 in | 52.25 in | A Currie replacement housing for this car is 57.375 in wide |
| Bronco | 1966–77 | 58 in | 53 in | 5-on-5½ in wheel bolt circle |
| Mustang, Cougar, Comet, Fairlane | 1967–70/71 | 59.25 in | 54.25 in | One entry lists the 1967 Cougar at 60 in |
| Mustang | 1971–73 | 61.25 in | 56.25 in | |
| Torino, Ranchero, Fairlane | 1967–73 | 59.25 or 61.25 in | 54.25 or 56.25 in | Depends on model and year; measure before buying |
| Fairlane (coil spring) | 1967 | 63.50 in | 58.50 in | |
| Lincoln Versailles / Granada | Late 1970s | 58.5 in (one entry says 58) | 53.5 in | Sources differ on the exact years |
| Big 9-inch | 1973–86 | 65.25 in | 60.25 in | 5-on-5 wheel bolt circle; the axles cannot be shortened |
| Ford van, 3/4-ton | 1972 | 68 in | 63 in |
Two cars on the same list are not 9-inch cars: the 1974 Maverick (56.50 in) and the 1975 Mustang II (57.00 in) use the 8-inch. If your car needs the 8.8 instead, use our 8.8 width chart.
For length, ratios and tag codes, see our 9-inch axle length chart, 9-inch gear ratio chart and 9-inch identification code chart.
How to Tell It Is a Real 9-Inch
- Removable third member. The center section bolts to the front of the housing.
- The wrench test. On a 9-inch the bottom two case nuts need a wrench; on an 8-inch every case nut takes a socket (JEGS).
- Nodular case. A nodular iron third member carries an “N” cast between two strength ribs.
- Year clues. JEGS describes a 1957 housing with no dimples and a bottom drain plug, 1958–59 housings with two dimples, and 1960–67 housings with two dimples and an oil level hole in the back cover.
- Gear tag. A tag reading 350 means 3.50:1. An L between the digits, as in 3L50, means a locking or limited-slip unit.
Design facts: the ring gear measures 9.00 in, the pinion is straddle-mounted, and the pinion sits 2.25 in below the ring gear centerline, up from 1.5 in on the 1956 axle, according to Wikipedia.
Housing Ends and Wheel Bearings
Ford used a small-bearing end on lighter passenger cars and two big-bearing ends. Strange Engineering lists the early big Ford end as used until the 1973 Gran Torino, and the late big Ford (Torino) end as used from 1973 through 1986. Both take the same axle bearings, but the backing plate and retainer bolt pattern differ.
| End type | Years | Bolt pattern (wide x tall) | Bearing and axle offset | Notes |
|---|---|---|---|---|
| Small Ford | Used until 1979 | Not published by the sources we used | Smaller axle bearing | Lighter cars with 28-spline axles; some Boss 302, 429 and 427 Mustangs with 31-spline |
| Early big Ford | To the 1973 Gran Torino | 3.5 in x 2.375 in | 3.150 in bearing; typical axle offset 2.332 in (some 2.500 in) | Larger bolt holes, so fewer brake options |
| Late big Ford (Torino) | 1973–86 | 3.556 in x 2.00 in | 3.152 in bore, 0.680 in deep; axle bearing ID 1.531, 1.562 or 1.772 in; typical offset 2.500 in | Smaller 3/8 in holes; most common aftermarket end |
Posters in a FordFE forum thread favor the Torino end because it is more compact and Torino and Aerostar drum parts, or Explorer rear discs, are easy to find for it. Both big ends use the same bearing, so you can only tell them apart by the bolt pattern.
Pinion and Carrier Bearings
The inner pinion bearing is a common question. For the Daytona-style pinion support, retailers including Broncograveyard list a Timken HM89443 cone and HM89410 cup, with a 3.000 in cup outer diameter and a 1.3125 in cone bore. We found no manufacturer-confirmed number for the earlier standard support, so measure the cup and match it before ordering.
| Bearing | Part numbers | Size | Used with |
|---|---|---|---|
| Daytona inner pinion | HM89443 cone, HM89410 cup | 3.000 in cup OD, 1.3125 in bore | Daytona pinion support |
| Carrier | LM501349 / LM501310 | 2.892 in OD, 1.625 in spool bore | 28 and 31-spline stock |
| Carrier | LM102949 / LM102910 | 2.892 in OD, 1.781 in spool bore | 28, 31 and 33-spline |
| Carrier | LM603049 / LM603011 | 3.063 in OD, 1.781 in spool bore | 33 and 35-spline |
Carrier bearing sizes come from a darkside.ca reference page. Wikipedia gives the factory center section bearing dimensions as 3.0625 in and 3.250 in. Confirm any part number against your own parts before ordering.
Axle Spline Counts
| Splines | Shaft diameter | How to spot it | Notes |
|---|---|---|---|
| 28 | 1.208 in | Oval hole in the wheel flange | Tapered axle; cannot be shortened, except 1969–73 Mustang and Cougar |
| 31 | 1.291 in | Two large holes and a countersunk center | Axles from 1972 and earlier can be shortened; 1973 and later big-car axles cannot |
| 33 | 1.333 in | Aftermarket | Race axle size |
| 35 | 1.500 in | Aftermarket | Needs a larger carrier and a spool or locker |
| 40 | 1.708 in | Aftermarket | Drag racing |
Ford built the 9-inch with 28 and 31-spline axles; 35 and 40-spline axles are aftermarket (Wikipedia). Diameters come from a darkside.ca reference page, shortening rules from JEGS, and the hole patterns from a 429-460.com forum compilation.
For other axle details, see our Ford axle code chart, F-150 rear axle ratio codes and Ford bolt pattern chart. For oil, see our gear oil guide for the Ford 9-inch.
Ford 9-Inch Width FAQ
What are the common Ford 9-inch rear end widths?
Axle widths, wheel mounting surface to wheel mounting surface, are 57.25 inches for the 1965 to 1966 Mustang and 1957 to 1959 Ranchero, 59.25 inches for the 1967 to 1970 Mustang, 61.25 inches for the 1971 to 1973 Mustang, 58 inches for the 1966 to 1977 Bronco and 65.25 inches for the 1973 to 1986 big 9-inch.
How do I measure a Ford 9-inch axle width?
Measure from the wheel mounting face on one side to the wheel mounting face on the other, not from the brake drums. A bare housing is about 5 inches narrower than that number.
How wide is the early Bronco 9-inch?
Published lists give 58 inches wheel mounting surface to wheel mounting surface for the 1966 to 1977 Bronco, with a 5-on-5.5 inch wheel bolt circle.
What is the bolt pattern on a Ford 9-inch rear end?
It depends which bolt pattern you mean. The early big Ford housing end is 3.5 inches wide by 2.375 inches tall and the late big Ford Torino end is 3.556 inches wide by 2 inches tall. The wheel bolt circle is 5-on-5.5 inches on the early Bronco and 5-on-5 inches on 1973 and later big 9-inch axles.
What is the inner pinion bearing size on a Ford 9-inch?
For the Daytona-style pinion support, retailers list a Timken HM89443 cone and HM89410 cup, with a 3.000 inch cup outer diameter and a 1.3125 inch bore. Measure the cup on a standard support and match it, because we found no manufacturer-confirmed number for it.
How can I tell a Ford 9-inch from an 8-inch?
On a 9-inch the bottom two case nuts on the third member need a wrench, while on an 8-inch every case nut takes a socket. The 9-inch third member also bolts to the front of the housing.
Should I use 28 or 31-spline axles?
Ford built the 9-inch with 28 and 31-spline axles. The 31-spline shaft is about 1.291 inches in diameter against 1.208 inches for the 28-spline, so it is the stronger choice, and it needs a matching carrier.
When did Ford stop making the 9-inch rear end?
Ford built the 9-inch from 1957 to 1986, and the 8.8-inch replaced it.
Related Ford Axle Guides
- Ford Axle Code Chart — decode the axle code on the door label
- Ford Rear Axle Width Chart — widths for later Ford axles
- Ford 8.8 Rear End Width Chart — the 9-inch’s successor
- Ford 9-Inch Gear Ratios — ratios by year
- Ford 9-Inch Axle Length Chart — shaft lengths
- Ford 9-Inch Identification Codes — tags and casting marks
- F-150 Rear Axle Ratio Codes — modern axle codes
Full axle & spec guide: Ford Axle Code Chart (F-150, F-250 & F-350)