The ’99-’04 Ford Super Duty ¾- and 1-ton trucks were some of the best-selling fullsize pickups of the day. Equipped with front and rear solid axles, leaf-sprung suspensions, potent powertrains, and plush interiors, the luxo workhorses helped kick off the diesel truck wars that are ongoing today. Given the tremendous aftermarket support, the trucks became a popular build platform for 4x4 enthusiasts of all types. Fast forward over a decade later, and the first-gen Super Dutys can be had for a fraction of the initial cost- making them more available to the masses.
While we are fans of the V-10 and heavyweight 7.3L V-8 trucks, the one less than desirable part on the early Super Duty is the Dana 50 front axle. Bolted under the front of the Super Duty well into the middle of 2002, and equipped on most 4x4 Ford Excursions, the Dana 50 front axle was a carry-over axle that Ford finally phased out officially by the end of 2003. Although the Dana 50 isn’t as robust as the Dana 60 that eventually replaced it in the Super Duty line, it is more than a glorified Dana 44 that people often perceive it as. In fact, the Dana 50 and 60 high-pinion Super Duty axles have more in common than you might realize.
As you may infer from its name, the Dana 50s overall size and strength rest between that of a Dana 44 and Dana 60. For those looking to run up to a 37-inch tire, the Dana 50 is well-suited. The weak points usually don’t begin to appear until you break into the 38-inch-plus knobbies. This fact was most apparent on our friends ’00 Ford Crew Cab F-250. Equipped with 40-inch Nitto Mud Grapplers, a tuned 7.3L diesel, heavy-duty body armor, and front and rear ARB Air Lockers, the daily-driven workhorse has seen its fair share of business and recreational use. After years of wheeling with smaller tires, and no issues, our friend opted to step up to a larger set of cleats. The end result was a destroyed ring-and-pinion.
Ultimately, a number of factors could have caused the breakage, but he’s opting not to take the chance again and upgrade. After making a few calls, he landed a Dana 60 from a ’04 Ford F-350. To see just what benefit the new-to-him 60 would bring and what commonality was between the 50 and 60, we stopped by to document the swap.
Step By Step
A major weak point on the Dana 50 (Right) is the 26-spline, 1.375-inch pinion. As you can see from the broken pinion pictured, it was no match for the load and stress of 40s and a powerful diesel engine. The new G2 Axle & Gear Dana 60 (Left) pinion sports a 29-spline count and comes in at 1.625 inches.
On paper, the 3/4-inch difference between the Dana 60 (Left) and Dana 50 (Right) ring gear may not seem like much, but a little can make a big difference. Sitting at 9 inches, the Dana 50 ring gear doesn’t have as much surface area as the 9.75-inch 60. The increased contact pattern on the 4.56 G2 Axle & Gear Dana 60 ring gear will also help to distribute load more effectively. Depending on what differential carrier you are running, you will need to specify whether you need a standard or thick gearset.
Both the Super Duty 50 (Bottom) and 60 (Top) have 1.50-inch axleshafts, but on the Dana 50 the ’shafts are machined down to 1.30-inch at the differential. The Dana 50 is also fitted with 30-spline inners, whereas the 60 gets 35 splines.
One area where there is no difference between the Super Duty Dana 50 and 60 is the U-joints. Both axles use a massive 5-806 universal joint, which is extremely strong in stock form.
Typically, the Dana 50 and 60 were both equipped with 1350 pinion yokes under the Super Duty. The snout on the Dana 60 is noticeably longer and on some applications may require the use of a new front driveline when swapping from the Dana 50.
A high-pinion axle is more desirable when placed in the front of a vehicle due to the pinion powering the stronger drive side when moving forward.
The Dana 50 axle being upgraded from had been previously fitted with an ARB Air Locker. Despite breaking the pinion and damaging the ring gear, the 50’s ARB was in perfect shape. Given the lockers flawless track record over the past 45,000 miles and numerous wheeling adventures, the trucks owner opted to install a 35-spline version of the ARB Air Locker in the 60. The selectable locker is an excellent fit for the long and heavy workhorse. The ability to act as an open diff provides increased maneuverability and makes using four-wheel drive a bit safer in harsh winter weather conditions.
A G2 Axle & Gear master install kit was used to set up the 4.56 gearset and ARB Air Locker. After the housing was drilled and tapped and the bearing cap notched, the ARB air line was carefully routed through the housing. The ARB Air Locker changes the Dana 60 differential from internal, to external shims, but setup time between the 50 and 60 is roughly the same.
The original Dana 50 from our friend’s ’00 F-250 had been upgraded with a Dynatrac combo kit. Luckily, the outer knuckles and ball joints are the same on both the Super Duty Dana 50 and 60, so he was able to reuse the high-end conversion.
Possibly the most troublesome part on the Super Duty Dana 50 and 60 is the factory unit bearings. Along with the vacuum-assist hubs, the stock unit bearing outers are known to wear more rapidly when equipped with larger tires and heavy off-road use. The Free-Spin kit from Dynatrac replaces the unit bearings with a more traditional full-float spindle. In addition to being serviceable (factory unit bearings are not) the Free-Spin kit spaces the bearing set to better handle the heavy loads of the 3/4- and 1-ton trucks.
The stock axleshaft outers on the Super Duty 50 and 60 are both 30 spline. With the Free-Spin kit, Dynatrac ups the shaft count to 35 and fits each with a Premium Warn hub. The combo kit is also rated for up to 44-inch-tall tires and retains the Super Duty 8-on-170 bolt pattern.
To finish out the axle swap, the Dana 60 was fitted with a G2 aluminum diff cover. The heat-treated and shot-peened cover is milled to help with cooling and fitted with a built-in dipstick and drain plug to make servicing the differential much easier. We’re also dig that it’s made in the USA.
There is no question that swapping from your Dana 50 to a 60 isn’t going to be dirt cheap, but it is likely the most cost effective way you can upgrade your Super Duty with a stronger front axle. We found the swap to be as straight-forward and bolt-in as it gets. U-bolts, steering, and stock brake calipers and rotors all carry over. Given that so many parts interchange, you can look for a 60 without outers, though you will need new inner axleshafts. If you’re only running 37s, maybe even 38s, you can probably get a lot of life out of your Dana 50. For anything larger, the added carrier strength and ring-and-pinion the 60 provides are well worth the investment. The total install time will vary depending on the condition of the donor 60, but it’s not unrealistic to have the job finished in a day with the right parts, tools, and know-how.