First thing that came to my mind is that your rear diff lock is stuck ON!
and making the rear of the van skip around like that.  I also drive with
my front drive shaft out (most of the time) and I get no such behaviour
(such that you describe)  out of my van.  malcolm

> a) having removed my syncros driveshaft b) truning sharp on an incline
> or upa kerb/ramp ...looking round I see a wheel is jacked up off the
> ground.