Don’t forget velocity drive, otherwise wheels will be shaking:
Swing Limit Soft should be off too, there was some sort of limitation when it’s turned on, don’t remember right now.
Angular Position Strength is a stiffness of the spring, set tank to it’s proper mass and tune this value up until you get proper clearance - distance between bottom of chassis and the ground. This is where I don’t like physics constraints as springs - if you change angle limit you have to tune Position Strength and Velocity Strength again, the wider allowed angle the more force you need.
The estimate for the spring strength is something like this:
Mass of tank in kg * acceleration due gravity / amount of wheels.
60000 * 980 /16 = 3675000 would be a basis.
Btw, in case you don’t know, you can multiselect all your suspension physics constraint by ctrl+left click in the list and then any change of parameters will be applied to all of them.