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These Danas are indistinguishable in appearance. The military Model 25 has a thick, cast cover, while the 27 and civilian-model 25s have a thinner cover, will accept taller gears, and backed V-6s.
The alloy-case Dana 28, with a 6 5/8-inch-diameter ring gear, came in Bronco IIs and Rangers with anything but the 4.0-liter engine. Although 4.0-liter trucks come with Dana 35s, most of the front suspension and/or drivetrain needs to be swapped to replace a 28.
The Model 30, with a 7 1/8-inch-diameter ring gear, was the standard front differential in some 1972-75 CJ-5s and all 1975-and-later CJ-5s and CJ-7s. It is still used in the front of Cherokees and Comanches, and will probably appear in the front of the Grand Cherokee.
This axle, with a 7.56-inch ring gear, is the fronted for 4.0-liter Ford Rangers and Explorers/Mazda Navajos. The 35C version is found in the rear of Cherokees and Comanches.
The 41, which has a ring gear size similar to the Dana 44, came in early CJ-2As. The spiders are the same as a 44's, but the carrier and gears aren't. It is almost universally swapped out in favor of a Dana 44.
All domestic manufacturers have used Dana axles, and the 44, with its 8 1/2-inch ring gear, is likely to be a step up on anything smaller than a 1/2-ton. A narrowed 44 could be the hot ticket for vehicles smaller than a full-size sport-utility. It was standard under the front of pre-1976 Chevy Blazers and 1/2-tons, solid front-axled F-150s and Broncos, and Jeep J-10/J-20s and Grand Wagoneers.
The Ford-version Dana 44 Twin-Traction-Beam setup is similar to other 44s (ring gear diameters are identical), but there are no axle tubes and the "cover" is actually the suspension arm. It's standard in the front of any TTB-equipped Ford except the 1987 and newer F-250HD, which uses a Dana 50.
A Dana 60 looks deceptively similar to a Dana 44, but the 60's 9 3/4-inch ring gear diameter is a major factor in strength. It can be found in many 3/4-ton pickup and van rear ends.
Almost identical in appearance to a Dana 60, the Dana 70 is standard in heavy Dodge pickups and GM duallies. The large 10.54-inch ring gear diameter will tolerate much torque, and is suitable for diesel power and/or big tires.
The small Ford rear end, which sometimes uses a fiberglass cover, is found in Bronco IIs and non-4.0-liter-powered Rangers. For bigger tires and/or engines, it's usually swapped for a Ford 9-inch.
The 8.8-inch debuted in 1983 Broncos and F-150s, and is now found also in 4.0-liter Rangers and Explorers/Navajos. It is easily distinguished from a 9-inch by having a cover on the back.
The venerable Ford 9-inch is both readily available and strong. Later models have bigger axle tubes and stronger housings. It was standard under 1966-88 F-150s and Broncos. It also came on many vans and the Lincoln Versailles (a popular axle for swapping because of the Lincoln version's disc brakes with parking brake).
Ford's biggest axle comes with semi-floating shafts in 1983-and-newer F-250s, and as a full-floater in F-250HDs and F-350s. Applications are similar to the big GM 14-bolt and the Dana 70.
GM CORPORATE 10-BOLT
The GM 10-bolt is named for the number of bolts on the cover; ring gear diameter is 7 1/2 inches. Variations of this can be found in the rear of GM S-trucks and some Isuzus, and in the front of S-trucks.
GM CORPORATE 10-BOLT
This 10-bolt, with a larger 8 1/2-inch ring gear diameter, replaced the Dana 44 that was used in the front of some pre-1977 GMs. It can also be found in the back of 1983-91 1/2-tons and in the front of 1983-87 1/2-tons.
GM CORPORATE 12-BOLT
The stronger 12-bolt, with an 8 7/8-inch-diameter ring gear, can be found in various 1964-82 GM 1/2- and 3/4-ton rearends.
GM CORPORATE 14-BOLT
The "small" GM 14-bolt has a 9 1/2-inch ring gear diameter. It was used in the rear of 1964-and-later GM pickups, and in the rear of 1984-91 3/4-ton Suburbans.
GM CORPORATE 14-BOLT
With a 10 1/2-inch-diameter ring gear, the biggest 14-bolt GM rearend looks much like a Dana 70, and is but a few thousandths of an inch shorter in ring gear diameter. This axle is commonly used with big engines and/or overly large tires. It was used under 1973-87 3/4-tons.
AMC MODEL 20
Used in 1976-and-later Jeep CJs, the Model 20 rearend is both strong and weak. An 8 3/4-inch-diameter ring gear provides strength; weaknesses are the housing itself and the axle-to-hub retaining method. Converting to one-piece axles or full-floaters gives this axle better stamina.
CHRYSLER 9 1/4-INCH
Mopar's 9 1/4-inch rearend can put a stop (notice the octagonal stop sign cover shape) to rearend woes on many lesser-equipped vehicles. Chrysler has used these since 1969, on 1/2- and 3/4-tons.
Close to eight inches in ring gear diameter, this rearend has been used on 1979-and-later 4Runners and pickups. The four-cylinder turbo and 1988-and-later V-6 models have larger side carriers and the same ring size in front.