on the top bone change the rotation axis from Y or Z to be on the x Axis (not of the bone but the X axis of the truck) if you have the same setup in the rear 1 coil and 2 dampers on each side, yeah it the best option one bone for each damper and the one that has the coil should be the same for both the coil and damper
IK bones tend to lag and move that way with the normal spintires suspension, colision axles can fix it but its a pain to set it up