Does anybody make aluminum Tamiya rig axle cases?

[Espeefan]

Interesting idea, Paul, but that sounds like to much of a hack job, at least for my tastes.

So the question is, how much weight can a Tamiya semi axle handle? How much torque can the differential gears take? Are there any hardened gear set upgrades available? I don't know what my tractor will weigh, when it's complete, but I want it as heavy as possible. 20 to 30 pounds? Will the axles survive? I know some of you guys haul heavy loads on trucks, but that's not running larger ag tires, with better traction.