If you want to run big wheels and tires, it’s probably smart to swap out the stock axle(s) on your truck or SUV for “beefed up” axle from an HD truck. Most HD trucks have axles that are designed for substantial abuse, making them a great upgrade for a Jeep or a half-ton truck.
Among the most popular “beefed up” axles are the Dana 60, Dana 70, and 14 bolt. In this comparison guide, we’ll discuss the biggest differences between these axles, and give you some food for thought. Because we offer products for all three axles, we think we can be impartial and talk about these axles in a way that’s helpful.
What’s a 14 Bolt?
Also known as the “corporate axle“, the GM 14 bolt is popular because it’s fairly common. Offered on select Chevy and GMC trucks and vans produced since 1973, the 14 bolt gets its name from the 14 bolts that are used to secure the rear differential cover.
There are two main varieties of 14 bolt axle:
- A full float 14 bolt, which has a 10.5″ ring gear
- A semi-float 14 bolt, which has a 9.5″ ring gear
While this axle has been in production for decades, there was really only one significant design change in all these years of production. This makes it a great choice for a lot of projects, as it’s easy to find parts and there are used axles available in a lot of junkyards.
Also, the 14 bolt axle was only used as a rear axle, unlike the Dana 60 and 70 axles, which have been used as both front and rear axles by various automakers.
What are Dana 60 & Dana 70 Axles?
Dana Corporation is a very large OE and aftermarket supplier of axles and driveline components. Dana axles have been used by all of the big OEMs at one point or another, including to this very day. The Dana 60 and Dana 70 are two heavy-duty variants in the Dana axle line, and are typically found in 3/4 ton and 1 ton pickup trucks. The Dana 60 has a 9.75″ ring gear, while Dana 70 has a 10.5″ ring gear.
The variety of Dana 60 and Dana 70 applications is confusing:
- Dana 60 axles are available in front and rear fitments; Dana 70s are more likely to be rear, but front axle Dana 70 axles exist (International used them, as did Dodge for a time)
- One Dana 60 or Dana 70 is not necessarily the same as the next. There are different sizes of axle housings, different diameter axle shafts, different spline counts, etc. It’s not safe to assume that parts from one Dana will fit another.
Because there are so many Dana variations available, it can be challenging to source the right one when you want to upgrade. On the flip-side, because Dana axles are so common (and were offered by multiple manufacturers), there are a lot of parts and upgrades available.
Believe it or not, the Dana 60 has been used in some passenger cars. Plymouth and Dodge offered them on some HEMI powered passenger cars in the 1960s.
What’s Better – 14 Bolt, Dana 60, or Dana 70?
The short answer is we don’t know – it depends on your situation. They’re all good axles, and they all have their pros and cons.
The longer answer is that you want to think about how you use your truck, your budget, what upgrades you’re planning to make, etc. There are six things to think about:
- Gear ratio, and whether or not you can live with the original gears.
- Does ring gear size matter for your application?
- Does the weight of the axle matter for your application?
- Do you want a pinion support? It’s good to have for off-road applications.
- Do you need maximum axle spline strength?
- Do you need to try and find one at a junkyard?
- Do you want to buy a lot of aftermarket upgrades?
The gear ratio is the number of teeth on the ring gear divided by the number of teeth on the pinion. For the same size ring gear, the bigger (shorter) the ratio, the smaller the pinion teeth must be. This means that there’s less material supporting the load surface, making the pinion teeth easier to break off or damage.
Both the 14 bolt and the Dana axles came with a variety of ratios from the factory. Here are the numbers:
- 14 bolt factory ratios: 3.23:1 to 5.38:1
- Dana 70 factory ratios: 3.07:1 to 7.17:1
- Dana 60 factory ratios: 3.54:1 to 7.17:1
There’s a pretty wide variety in ratios, which is good and bad. Good, it that there are a lot of options available to you if you’re planning to upgrade. Bad, in that it can be hard to find a used axle with the “right” gear ratio.
If you can find a used axle with the right ratio, that saves you some money. If not, you can buy a new set of gears easily enough (they’re just not always cheap to replace), but that increases your costs.
Larger Ring Gears
Ring gear diameter is a pretty good indicator of overall axle strength and durability. So the bigger the ring gear, the stronger the axle (generally speaking).
Both the the full-float 14 bolt axle and the Dana 70 have a 10.5″ ring gear. The Dana 60 ring gear is 9.75″ in diameter, and semi-float 14 bolt axles have a 9.5″ ring gear. Because they have larger ring gears, the pinion on 14-bolt full float axles and Dana 70s is less likely to be damaged than the pinion on a Dana 60 or 14-bolt semi-float. This is important for off-roading, where people are typically using a 2 speed transfer case. The low range of the transfer case multiplies the torque that the differential must handle. The diff can see very high amounts of torque, especially when rock crawling.
Having said this, the Dana 60 and the 14 bolt semi-float are reliable axles.
The 14 Bolt and Dana 70 axles are Heavier Than a Dana 60
The typical 14 bolt axle weighs about 550 pounds. Since there are many different variations of Dana 60 and 70 axles, we can’t give those axles a certain weight. However, a rear Dana 60 axle usually weighs about 400 pounds, a front Dana 60 will weigh about 500 lbs, and the Dana 70 is similar in weight to the 14 bolt.
The 14 bolt axle and the Dana 70 weigh more partly because they have 3.5″ axle tubes, which are slightly larger than the 3 3/8″ tubes found on many Dana 60s. This helps the tubes resist bending when side loaded by large tires. The 14 bolt and Dana 70 also have larger axle shafts, ring and pinion gears, and brakes than the 60, which helps to account for the difference in weight.
While a 100lb difference in axle weight might not seem like much, it can have a pretty big impact on vehicle ride and handling. The lighter the axle, the better the ride (generally).
NOTE: If you convert the drum brakes on an axle over to disk brakes (using one of our kits, cough), you’ll save about 80lbs. The drums are very heavy on vehicles with these big, beefy axles.
Pinion Support – Only on a 14 Bolt
The 14 bolt axle has one key advantage vs the Dana 60 or 70. The 14 bolt has a pinion support bearing in addition to the conventional pinion bearing. The pinion support bearing supports the rear end of the pinion gear shaft. The extra support keeps the pinion from deflecting sideways under high torque. This is important when off road, where most are using a transfer case that is multiplying the torque to the drivetrain when it’s in low range. By contrast, Dana 60 and 70 diffs only have the conventional pinion bearing that supports the middle of the pinion shaft.
Spline Diameter – A Key Strength Factor
The diameter of the axle shaft at the splines is a key factor in determining how much load the axle can take:
- The 14 bolt axle and the Dana 70 each have axle shafts that measure 1.5″ at the splines.
- The 14 bolt has 30 splines while the Dana 70 has 35. However, the shape and design of the splines is different on the 14 bolt than on the Dana 70, so having only 30 splines is not considered a weakness.
- The Dana 60 is axle shaft has 30 splines, and they measure about 1.3″ in diameter.
While a .2″ difference in diameter between the Dana 60 and the Dana 70 doesn’t seem like it would matter much, it matters a great deal. The torque rating for a stock Dana 70 axle shaft is 8966 ft/lbs, which is almost 50% stronger than the stock Dana 60 axle shaft, which has a rating of 6044 ft/lbs.
NOTE: You may be surprised at how high those torque ratings are as compared to the torque your engine puts out. First, remember to multiply your engine’s torque rating by whatever your transfer case’s low range gearing is. OEM transfer cases typically have low range gear ratios running between 2 and 4 to 1. Aftermarket cases can have even lower gearing. So it’s not hard to have 1000 ft/lbs or more of continuous torque applied to the drivetrain. But what really stresses axles is the instant torque that is applied when tires lose and regain traction. Those instant forces can be much higher than the continuous forces.
It’s Much Easier to Find Used 14 Bolt Axles
Junkyard axles aren’t as easy to find as they used to be, but there are still a good number of 14 bolt axles available. In addition to junkyards, you can often buy 14 bolts on forums, in Facebook groups, etc. And because the 14 bolt axle is a popular upgrade, people who own one will often hold onto it because it has value.
Dana axles are harder to find. Part of the problem is that they’ve been popular with enthusiasts for a long time now, and junkyards have been picked clean. While you can certainly still find a used Dana 60 or Dana 70 axle, you’ll have to do some digging to find it. And when you do, the price of the axle will almost certainly be greater than a similar condition 14 bolt.
Finally, speaking of used axles, it’s often easier to find used OEM parts for a 14 bolt than a Dana 60. This means that, if you have a 14 bolt, you don’t have to go out and buy an aftermarket axle shaft if/when you break one. You can probably pull one from a used 14 bolt somewhere.
The Aftermarket Loves The Dana 60
If you’re looking for a used axle that you can build-up, a Dana 60 might be the axle for you. While there are a considerable number of upgrades for Dana 70 and 14 bolt axles (with more and more parts available every year), the Dana 60 is the king of the mountain. Just about every single part you might want to buy is available for a Dana 60…if you want something sort of special, odds are good you’ll find it for a Dana 60. The same can’t be said for a 70 or a 14 bolt (only it’s gotten better in the last 10 years).
Tip: Saying You Have A “1 Ton Axle” Doesn’t Say Much
One thing that’s confusing about the Dana 60 axles is that a Dana 60 in front is usually considered a 1 ton axle, and a Dana 60 in the rear is usually considered a 3/4 ton axle. Most trucks that came from the OEM with a Dana 60 in front were paired with a Dana 70 or 14 bolt axle in the rear, and they were both called 1 ton axles. This is most likely because the rear axle in a truck carries more weight than the front (when loaded). As another example, many Ford 3/4 ton trucks came with a Dana 44 in front, and a Dana 60 in the rear.
Likewise, while most 1 ton Chevy and GMC trucks and vans feature a 14 bolt rear axle, they can also be found in three-quarter ton trucks, vans, and SUVs (Suburban). And a semi-float 14 bolt (aka 9.5″ ring gear 14 bolt) can also be found in a few 3/4 ton trucks, vans, and SUVs.
Dana 60, Dana 70, And The 14 Bolt – They’re All Great
Like we mentioned, we don’t have any skin in the game in terms of which axle is best. We sell disk brake conversion kits for the 14-bolt axle, and the rear axle Dana 60 and Dana 70, as well as many other axles. The reality is that all three axles are strong, reliable axles for on and off road use.
Often times, choosing the best axle comes down to what you have available. If you’ve got a buddy with one of these things, and he’s willing to make you a deal, that might be the best choice.