The shackle still has to move because as the suspension goes through its travel the spring changes length. So it has to move.
Ok so now I understand that the arc of the spring will make the shackle move which I can see. So I assume 2 things. The rear shackle can only move backwards because that is the path of least resistance OR does the rear shackle movement forward only happens between rear shackle and the U bolt seat. Any further forward than that the Caltrac stops it. I have spoken to some that say basically Caltracs make the rear spring redundant and just a mechanism to hold the rear end in. That is not my view but I still would like to understand what happens to the rear shackle and spring under extreme acceleration with the Caltracs. I have looked on You Tube but cant see any footage pointed directly at rear shackle with Caltracs.
It also intrigues me that some Mopars with Caltracs Squat then move forward and some lift and propel forward but I suspect that has more to do with shock absorbers and thats probably for another thread.
