If you plan on running large tires and big horsepower, these are your go to axles. Rated at 9 ton, the planetary gearing in the hubs helps take stress off the rest of the axle components, making for an extremely strong yet compact axle. The newer axels also have a lot of better components, things that are machined are fit to closer tolerances and parts like seals and bearing are designed better than some of the older Rockwell parts.
What Are Some of The Benefits the Axletech 4000 Have Over the Rest of The Military Axles?
The Axletech's main advantage is its features vs cost. The fact that the Axletech 4000 comes with air locking differentials, 9 ton rated strength, tight 42 degree steering and disc brakes that can easily be set up for hydraulic calipers, is a big selling feature for the axle. Sure, most axles can be set up with those options, but usually at quite a high cost, the Axletech however comes with these from the factory.
When it comes to surplus axles these are the main choice for on-road 4wd conversions, the higher 5.65 ration in the narrow version, disc brakes and selectable lockers make these very desirable for the street.
Axletech axles also have a symmetrical bolt pattern that holds the differential to the housing, this means you can easily remove the differential and flip it upside down, this allows you to change the direction of the axle’s rotation, perfect for a rear engine application.
Why Don't I Want Axletech Axles?
They are heavy, with brakes in the factory configuration, you’re looking at 1500lb per axle. These can be lightened up a bit by removing some of the heavy stock parts, weights under 1000lb will take quite a bit of work and $. They're wide, the narrow versions of the Axletech axles still have an 85" WMS, there are a couple companies that are building custom narrow axles, but extra cost can be associated with this mod.
The newer axles with planetary wheel ends, are somewhat more difficult to work on compared to the old Rockwell axles. There are more moving parts and tolerances that need to be considered. Field repairs will not be as easy with the newer axles, as planetary parts will need to be kept clean and proper assemblies or expensive failures could occur.
The center pinion design can be difficult to fit under low slung rigs, as the front drive shaft will need to be run under or around the oil pan,
The survivability of the Axletech is limited, due to newer manufacturing methods the Axletech don’t have as many serviceable parts as older axles, the differential carrier on the 4000 units is all 1 piece the ring gear is welded to the carrier and the carrier itself is welded together, meaning the entire carrier/ ring and pinion will need to be replaced if there is ever a failure with any of those parts, also the outer planetary gears are sold as a complete set with the outer hub, surplus parts are available but those parts will eventually be exhausted
What Are the Differences Between The 2 Styles of Axletech Axles Showing Up?
There are 2 versions of the common Axletech axles showing up in military surplus, often referred to as wide or narrow versions. The "wide" version has a 90" WMS for the steering axles and an 87.25" WMS for the solid axles. The wide versions also come with a 6.84 gear ratio and no CTIS. Although rear versions of the wide axles are available, the front axles are more common, another distinguishing feature of the wide axles is an oval shaped pinion flange that accepts keyed u-joints. The "narrow versions of the at 4000 have an 85" WMS for the steering axles and 82.75" WMS for the solid axles. Narrow versions of the at 4000 come with 5.4 gear ratio, CTIS and a round serrated pinion flange. Used versions of these axles were available for a while and steering + solid axles were common, there are also tandem versions of the Axletech 4000 that have a through shaft and a pinion yoke on either side of the axle, as far as I’ve seen these have only been available in 6.84 ratio.
Minor differences between the 2 axles is the narrow version has a shorter passenger side axle tube and axle shaft, the narrow version of the Axletech simply looses 5" of its width by shortening one side of the housing, also besides the housing being offset the narrow version of the housing has a round shaped axle tube while the round version has a more square style, the king pins also differ between the 2 axles, both axles use the same drop in style king pins but the wide version uses a smaller pin where it fits into the lower part of the inner C, both axles use the same upper king pin, the reason for the changes is some of the narrow axles experienced damage where the king pin fit into the housing under heavy armor military vehicles the had a tendency to oval out that part of the knuckle, adding more material in that area seemed to a fix for the issue
Are Axle Supplies Drying Up?
There is a bit of speculation on this subject, when these axles first hit the market as used surplus there was a huge supply of new and used axles. From what I understand the us government sold off a pile of these axles essentially flooding the market. At this time, the at 4000 had not seen much to any use in the off-road industry so it took a while to gain in popularity, this helped keep supplies plentiful and costs down. Then for a short period of time the axle’s popularity grew quickly and suppliers sold out, after the big influx of sales, the price of axles started to climb in relation to demand. This has kept a steady stream of axles in stock with most suppliers. As of right now there are rumors that the us government still has large supplies of these axles that will eventually come up for sale, and they are available to anyone who is willing to purchase large quantities at one time.
Are Replacement Parts Impossible to Get?
yes and no, because the axles are still in production by Axletech new parts are available, however they can be difficult to get for the average person. There are rules against selling certain parts designed for and used in military vehicles to civilians. Parts are starting to become available and western Canadian Rockwell does have stock on common wear items like seals and u-joints. Most parts used on the Axletech axles are metric in size and common only to Axletech, this can make things somewhat difficult as they most likely won’t be available to your local auto store, also making things somewhat expensive. Keep in mind that the parts used on these axles are very high quality and won’t have to be changed on a regular basis, such as some of the older Rockwell axles.
Physical Weight and Dimensions/ Specs
Pinion is offset in chunk 2.5" to the driver’s side.
Hub OD: 15"
Overall height of axle (chunk area): 12.25"
Wheel Pattern 10x335mm
Axle Shafts 1.625" OD 33 spline
Hubs are 3.55:1
Ring and Pinion 1.59:1
Font WMS 85"
Rear WMS 82.75"
Overall width front 90"
Pinion flange is a crosscut style.
Axle comes equipped with Central tire inflation, air lockers, 42-degree steering, pneumatic disc brakes.
Hubs are 3.55:1
Ring and Pinion 1.84:1
Font WMS 90"
Rear WMS 87.25"
Overall width front 95"
Axle tube OD:
These are an oval cast tube with no exact dimensions.
Rear 41.5 " center to center pad is 3" x 7.5"
Front 34.5 " center to center pad is 3.5" x 9.5."
Pinion flange uses a winged style U-joint.
No central tire inflation
Axle comes equipped with air lockers, 42-degree steering, pneumatic disc brakes.