Yeah that looked like some homemade variation of a Hendrickson Suspension to me too. Hendrickson's was tough & had a rhythm of their own....thumpity-thump, thumpity-thump, thump, thump! Didn't make any difference what wheelbase the rig was, it rarely was ever on a smooth riding road. It'd get started thumping on a roadstripe & 'ya had to cinch up & start holdin your GUTS! & I figure he needs
all those shocks, maybe more!
I can't figure out how he splits it either. Driveshaft is coming into front axle normal like. I'm not aware of small truck setup available with interlock & powerdividers etc to drive that rear axle like bigger semi's, but I don't know everything either.
Actually, the suspension with that long "walkingbeam equalizer" setup looks a lot like couple older smaller equipment trailers I've seen.
But how he drive that rear axle? V belt or chain drive off some other driveshaft? Drive it off PTO setup? Wind it up with rubberbands & "let-go" with that Airswitch he mentioned??
6 wheel drive at slow speeds, or highway speeds??
Inquiring minds want to know!!!