Most of the heavy duty trucks built between 1968 and 2000 came with either a 3/4 ton axle or a 1 ton axle. If you need to identify which axle you have on your truck, this guide is for you.
An Easy Way To Identify Which Axle You Have
You could check a service manual or look online to find out which axle your truck came with. It’s not a foolproof way to find out which axle is on your truck, though. It’s very possible that your truck no longer has its stock axle. Maybe a previous owner installed a different axle on the truck.
Luckily, there’s an easy way to find out which axle is on your truck right now. All you need to do is look at the differential cover.
Checking The Differential Cover
You don’t need anything special to do this job. Just slide under and count the bolts on the diff cover. There should be 10, 12, or 14 bolts holding the cover to the differential.
How Many Bolts Does Your Differential Cover Have?
Now that you have counted the number of bolts around the differential cover, you can determine which axle your truck has.
10 Bolts: Dana Axle
The Dana axle is found on many different makes, including:
There are many different Dana axles. But if it has 8 lugs, it’s a Dana 60, Dana 70, or Dana 80. To determine which one you have, check the number of splines your axle has. If it has 30 splines or less, then it’s a Dana 60 axle. If there are 33 or 35 splines, then you have a Dana 70 axle. If you have a 1994-2001 Dodge you may have a Dana 80 axle which also has 35 spline axle shafts.
There are three variations of the Dana 60 axle. Each variation fits a certain make or set of makes. This guide will help you identify which variation of the Dana 60 axle you have on your truck.
12 Bolts: Sterling Axle
Made for Ford, the Sterling axle had two variations. If your vehicle has the axle that came from the factory, and the brake system is stock, it’s easy to tell which axle you have. All:
Sterling 10.25″ axles came with drum brakes. They have an 8 x 6.5″ lug pattern and were used in 1997 and older trucks.
Sterling 10.50″ axles came with disc brakes. The have and 8 x 170mm lug pattern and were used in 1999 and newer trucks.
If you’re not sure the axle is original, or if the brake system has been altered, there is another way to determine which Sterling axle you have. You can simply measure the ring gear. Obviously, this method is more difficult and time consuming.
Fords that had original equipment disc brakes used dual piston calipers. When an axle is converted to disc brakes, most kits, including ours, use single piston calipers. This is another way to determine if your axle has OE disc brakes, or if it was upgraded.
14 Bolts: 14 Bolt Axle
The name of the axle is pretty self explanatory. It has 14 bolts on the differential cover. This post offers a good overview of the 14 bolt axle.
The 14 bolt axle come in two varieties:
- Full float 14 bolt with a 10.5″ ring gear
- Semi-float 14 bolt with a 9.5″ ring gear
Exceptions To The Rule
Many millions of heavy duty trucks were produced between 1968 and 2000. The information above applies to the vast majority of HD trucks, but there will be exceptions that were produced in small numbers. Also, the axles above were used in some vehicles well before 1968. But axle usage prior to 1968 wasn’t as standardized as is was in the 1968 to 2000 timeframe. If you would like a visual reference, we have created one for the GM 14 bolt axle. This guide will help you identify which 14 bolt axle you have.