Subscribe to a magazine

Our Favorite Jeep Axle Swaps

Dana 44 Axle
Christian Hazel
| Brand Manager, Four Wheeler
Posted September 1, 2011

Go-To Guys

If you’ve got a Jeep, then you’ve probably come to realize that factory axles are an exercise in mediocrity. Once the vehicle is even slightly modified, their strength always seems to be one step behind the demands of the Jeep’s newfound capability. Snap, pop, and bend is often the result.

Sure, you can upgrade what Toledo gave you to work with. But in many cases it’s better to forget the factory axles and head straight for better options. Usually, a little time spent searching and setting up a stronger set of axles not originally offered in your Jeep model will pay big dividends down the road in terms of strength, survivability, and sanity. So with that said, and in no particular order, here are some of our go-to axles when our trail needs write a check our factory axles can’t cash.

Rockwell 2.5-ton Front/Rear
Found in: Military M35A2 2.5-ton 6x6 trucks
Width between wheel mount surfaces: 79½ inches (hubs out) or 69¼ inches (hubs flipped)
Shaft diameter/spline: 1.62-inch, 16-spline
Common gearing: 6.72
Bolt pattern: 6-on-8 3/4

Pros: They’re strong and inexpensive to buy when compared with 1-ton Dana axles. The double-reduction style centersection can be flipped with a little work to help in drivetrain clearance. Aftermarket steering arms and pinion brake components can be bought or fabricated relatively cheap. They’ll stand up to a good deal of abuse with tires up to 45-inches.

Cons: The shafts aren’t metallurically as strong as modern offerings, so 46-inch and larger tires can take their toll. Additionally, the 6.72 gearing and huge physical size favors at least a 42-inch tire and creative fitment to clear engine and drivetrain. In addition to the small tire size window, the bolt pattern will really limit wheel selection. Once you get into aftermarket shafts and at-the-wheel disc brakes things get expensive. Rockwells are best run in stock (or near-stock) form or not at all, but if you’re running high-horsepower and big meats you’ll have to have really deep pockets to keep your Rockwells alive.

Full-Size Dana 44 (GM/Dodge)
Found in: ’73-’77 Chevy ½- and ¾-ton pickup, Blazer, Suburban; ’80-’84 Dodge ½- and ¾-ton pickup and Ramcharger
Width between wheel mount surfaces: 69 inches (Chevy); 67 inches (Dodge)
Shaft diameter/spline: 1.31-inch, 30-spline
Common gearing: 3.23, 3.54, 3.73, 4.09, 4.56
Bolt pattern: 5-on-5½ (Dodge ½-ton); 6-on 5½ (Chevy ½-ton); 8-on-6½ (Chevy/Dodge ¾-ton)

Pros: They’re still easy to find in junkyards and have one of the strongest aftermarket support systems in place. All Dodge and some Chevy versions have flat-top knuckles for conversion to crossover steering in spring-over applications. Dodge ¾-ton housings have shorter distance between ball joints, so swapping to ½-ton knuckles allows long-side to be shortened for narrower WMS measurement and still work in early Jeep without outboarding springs. Chevy versions can be swapped to 5-on-5½ Ford hubs/rotors easily. Almost all ¾-ton versions came with 4.09 or 4.56 gears.

Cons: Most don’t want to shorten long-side tube and/or outboard springs for use in CJs and YJs. Dodge knuckle versions are unique with few interchangeable parts between other brands or even between ½- or ¾-ton Dodge axles. To go from ½- to ¾-ton you must swap whole knuckle.

FSJ Dana 44
Found in: ’74-’91 Wagoneer, Cherokee, Cherokee Chief, J-truck
Width between wheel mount surfaces: 59½ inches (narrow-track Wagoneer/Cherokee S front); 58½ inches (narrow-track Wagoneer/Cherokee S rear); 66 inches (wide-track Cherokee Chief/J-truck front); 65 inches (wide-track Cherokee Chief/J-truck rear)
Shaft diameter/spline: 1.31-inch, 30-spline
Common gearing: 3.23, 3.54, 4.09
Bolt pattern: 6-on-5½ or 8-on-6½ (some ¾-ton J-trucks)

Pros: The Quadra-Track FSJs have Dana 44 rear axles offset to the passenger-side, which makes use in early Spicer 18-equipped Jeeps nice. The width is more manageable in most CJ and Universal vehicles, and when used with a spring-under front suspension the stock steering can be adapted with little trouble.

Cons: The 6x5½ bolt pattern is only easily converted to 5x5½ on the ’74-’76 small-bearing spindle models. Some early ’80s fronts were a CAD vacuum-disconnect design that should be avoided. Normally have to outboard the spring perches on CJ and YJ Jeeps unless narrowing long-side tube.

GM 14-bolt Rear
Found in:’73-’01 GM ¾- to 1-ton pickups, vans, Suburbans
Width between wheel mount surfaces: 67½ inches (pickup/Suburban); 70 inches (van); 72 inches (duallie pickup)
Shaft diameter/spline: 1.5-inch, 30-spline
Common gearing: 4.11, 4.56
Bolt pattern: 8-on-6½

Pros: You can find this 10.50-inch ring gear axle at virtually any junkyard and take it with you for $75-$200 depending on your location. Parts are easily obtained and it uses one of the least-expensive Detroit Lockers offered thanks to its sturdy factory split-case carrier. They’ll stand up to huge abuse and 44-inch tires in stock form.

Cons: The bottom of the differential hangs pretty low, so large tires or cutting the pumpkin are necessary for good ground clearance. The 1-ton drum brakes are massive, so swapping to aftermarket disc brake brackets with junkyard ½-ton calipers may be desired.

30-spline CJ Dana 44 rear
Found in: ’70½-’71 CJ (offset); ’72-’75 CJ, Jeepster/Commando (centered)
Width between wheel mount surfaces: 51 inches
Shaft diameter/spline: 1.31-inch, 30-spline
Common gearing: 3.73, 4.27, 4.88
Bolt pattern: 5-on-5½

Pros: The CJ versions are a bolt-in solution to virtually any ’75-earlier Jeep CJ that gets you one-piece, flanged 30-spline shafts inside a decent housing that’ll stand up to street driving and moderate off-roading. It’s a great find for street-driven restorations or vintage wheeling builds.

Cons: Some non-CJ/flatfender models may need axle pads moved. The ’70½-’71 offset models are becoming exceedingly rare and pricey. The narrow 51-inch width doesn’t make it a great choice for a hardcore build.

High-Pinion Dana 30
Found in: ’95½ -’00 Cherokee
Width between wheel mount surfaces: 60½ inches
Shaft diameter/spline: 1.16-inches, 27-spline
Common gearing: 3.55, 4.10
Bolt pattern: 5-on-4½

Pros: The ’95½ Cherokees got upgraded axleshaft U-joints from 260X to Dana 44-size 760X. That, coupled with a high-pinion design makes it a great bolt-in upgrade for the TJ Wrangler low-pinion or older Cherokee low-pinion or CAD front axles. You can also cut off the brackets and weld on spring perches for use in YJ vehicles without too much hassle.

Cons: The axletubes are somewhat weak, so you’ll want to at least bolster them with a set of EVO Sleeves from Off Road Evolution or build a truss to help survivability in heavy off-road use.

Disc-Brake CJ Dana 30
Found in: ’76-’81 Jeep CJ (narrow-track); ’81½-’86 CJ (wide-track)
Width between wheel mount surfaces: 51 inches (narrow-track); 56 inches (wide-track)
Shaft diameter/spline: 1.16-inch, 27-spline
Common gearing: 2.73, 3.54, 3.73, 4.09
Bolt pattern: 5-on-5½

Pros: With some slight work to accommodate the 2-inch-wide spring pads and steering, the open-knuckle, disc brake Dana 30 is a bolt-in upgrade for virtually any ’41-’76 drum-brake CJ or Universal. They’re good for tires of roughly 33 inches in stock trim, but can be upgraded with larger chromoly 30-spline aftermarket shafts to bump that up a bit.

Cons: Despite the potential for better-than-Dana 44 shaft strength, the low-pinion gearset will remain the weak point, so gnarly off-road builds with big tires aren’t for this axle. The narrow-track versions are best kept off the extreme rigs as well. Also, the later five-bolt external-body hubs require periodic bolt maintenance to ensure survivability.

Load More Read Full Article