I can remove the linkages from the rearend and it stays in place and moves the exact same that it would with the linkages "attached" to it. Do the rear linkages not react upon the beam axle? Theoretically the left side at a higher angle should drive the left rear down faster than the right rear.
Just something I was wondering because if they don't act upon the rearend depending on angles, modding the rearend to a "realistic" status would be difficult to accomplish "realistic" car attitude.
There is a known bug in the beam axle simulation.
It will be fixed as soon as possible.