By tighten, do you mean stiffen?
If so, the jam nuts on top of the spring are not used to stiffen the shocks. They are used to adjust ride height. To stiffen the shocks, you have to adjust the compression which is the knob on the shock resivior. Turn it to the right (tighten) to stiffen the suspension.
If so, the jam nuts on top of the spring are not used to stiffen the shocks. They are used to adjust ride height. To stiffen the shocks, you have to adjust the compression which is the knob on the shock resivior. Turn it to the right (tighten) to stiffen the suspension.