Was the square key for the helix in the secondary in place so you could pretension the spring by 1/3 of a turn? The reason I ask is because I had one push out when I installed the helix and had basically the problems you are having.
I think that might be it. When I took it off the secondary, the round hollow bearing(?) and key just fell into the belly of the sled when I was removing it. BUT I did have to twist it and push down to get the helix to pop out to take the secondary apart. Does that mean it was pre wound or would that not matter?