There's no debating that the Dana 60 is the toughest rear axle going if maximum strength is the mission. And contrary to popular belief, at 250 pounds drum-to-drum (O.E. Mopar or aftermarket automotive version), a typical Dana 60 is only 50 pounds heavier than an average Ford 9-inch. But many Car Crafters may be unaware there are several other Dana rear axles with similar appearances that are smaller and weaker. The big dog Dana 60 gets its strength from a massive 931/44-inch ring gear, which provides more gear-mesh contact area for greater load-bearing capacity, thickly webbed carrier- and pinion-bearing support sections, and beefy 30- to 35-spline axleshafts. Here's a junkyard tour to help you identify the 60 series and avoid the weaklings. So remember, regardless of what the guy at the swap meet says, just because it has a drain plug in the cover doesn't mean it's a Dana 60.
Studebaker, Willys (Jeep), Packard, and Kaiser-Frazer were independent, postwar carmakers without the resources to tool their own rear axles, so they sourced them from Dana. This is a Dana model 44 as found under a typical Studebaker. Note the protruding castle nut in the center of the brake drum, an indicator of weak and trouble-prone two-piece axles. Jeep used a variant of this axle for more than half a century. Even smaller model 35s and 37s also appeared.
Industry giant Mercury was also a Dana customer before the 9-inch arrived in 1957. With the introduction of the revolutionary '49 Mercury, the company got rid of the old torque-tube setup and used Dana model 45 axles with open driveshafts like the one under this '56 Mercury. Visually similar to the model 44, these Mercury units have 8.5-inch ring gears and were all built with one-piece, semifloating axles. Beginning in 1985, a variant of the model 45's differential assembly was used in stick-shift-equipped C4 Corvettes.
While Ford and Mercury cars dropped the Dana 45 for the home-brewed 9-inch in 1957, Lincolns stuck with Danas into the '60s. Here's a Dana model 53 under a '64 Continental. Like the FoMoCo-spec model 45, these Lincoln axles also had one-piece, semifloating axleshafts. Though it looks pretty rugged, and limited slip was optional, stock 2.89 or 3.11 gear ratios kill it for high-performance use. In 1966, Lincoln ended its Dana period and switched to a variant of the Ford 9-inch: the 931/48, another oddball axle with limited ratio availability.
Like all Dana axles, the super duper model 60 is identifiable by a number cast into the lower righthand corner of the housing. New reproductions by Moser and Strange may or may not have this number. A sure-fire Dana 60 indicator is the distance between the outermost inspection cover bolts. If it's 1011/44 inches, go ahead and dump the clutch. Anything less and you're looking at one of Dana's little sisters.
*The largest passenger-car ring gear of the postwar era is the massive 10.5-incher used in the original FWD '66 Olds Toronado
*In 1913, financier Charles A. Dana loaned Spicer Manufacturing $15,000 to expand operations. By 1915, Dana was the president of Spicer Manufacturing. Ever since, the two names have been synonymous with driveline components.