WHY DO I WANT AXLETECH 4000 AXLES?
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 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.
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.
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.
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 supply's 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?
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"
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"