Idea for a pusher axle

it would be tag axle. Europeans use to build rigid trucks with tag axle.

but..... EU drive axles are of higher torque ratio, so I'd limit engine torque at low speeds.

 

The rear carrier is not meant to be used as a single axle. The torque is too much for it. A tandem is set up to be a tandem as far as torque goes. A true single rear has a higher torque rating. The front rear will be able to handle the toque. Just look at the size of the drive shaft, U joints, and yokes on the rear rear. You could experiment without much expense to see if what you want will work. Get a manual air valve that will exhaust one side and hold pressure on the other. Then plumb it into the rear air bags to see if letting the pressure off the rear gets you the traction you want. You will of course need to engage the power divider when you "dump" an axle. Then you can latter change the plumbing to "dump" the front drive. An air tailgate switch will work. http://www.finditparts.com/t/396/manufacturer/velvac/products/506501/velvac-320151

 

Making the rear axle the dead one conveniently eliminates the need for a drop axle or other trickery to accommodate the driveshaft. That's what I'm planning on doing, but I'm sourcing a different rear end for the driven axle (with a locking diff). Also planning to make my rear axle lift as well as dump air( dump for temporary extra weight on drives in slick slow spots, lift for running empty).

That's the plan anyway...

 

So, you would need to make a plug to go in the end of the spindle to seal the oil on the hubs for the bearings. Then make a plate to go where the axle shaft bolted to the hub. Cut a hole in the plate to mount a trailer hub oil cap. Then you could cut a hole in the banjo to put your drive shaft through. Thoughts?

 

I'm not planning to lift the axle with any load at all, but I can see your point. And, the dump would only really see use in situations where heavily loading the driven axle would be useful, such as driving out of a parking spot that had been plowed in with snow. And, I've got a fairly long 5th wheel slide and chassis, so I can reposition as necessary.

What sort of regrets are you finding from drivers with lifting tags? I don't know anyone who has this sort of setup so I can't pick anyone's brain in person.

 

The lifting tag would be great, if you could get the fifth wheel far enough forward. You would end up with the turning radius of a compact car. The only problem would be the negative affect on the steer weight.

 

I converted my truck to a single drive with a lift about 4 years ago. Love it. removed entire front axle and replaced it with a drop center trailer axle. manual lift on the axle. I did the conversion myself.