I doubt you can take a semi truck axle and narrow it to fit under an AD truck.
There is a limited amount of room between the centerline of the wheel and the frame/springs. A semi truck axle has a lot of stuff in that space, to much stuff.
There are some medium duty axles with air brakes that will come closer to fitting, but I still think you'll have a difficult time making it work.
Check some imported cab over trucks, they're generally smaller and may be small enough to work?
Not all that many semi trucks come with air ride front suspension.
Not that you can't make something, but just having a semi truck front axle doesn't get you a workable front air suspension.
I too am on the lookout for air brakes for my 2 ton. What I'd really like are air disc brakes that I can adapt to fit my current P-30 axles.
So far all the air disc brake calipers take very specific size rotors, (no room to fudge on diameter) and the one caliper that looks suitable for my truck accepts a rotor that is no where close to adapting to fit, and I can't find any substitutes that are any better just yet.
Give it a few more years for more of the air disc brakes to trickle in from Europe and I bet we start seeing ones that might work, probably on delivery trucks and other medium duty stuff.
If you want to pretend you have air brakes you could use an air over hydraulic setup. Not saying it's a good idea, but it is an option.
Grigg
