Sider Joint 2D in 3D

How do I set up a Configurable Joint so it behaves like a Slider Joint? I know how to restrict movement to one axis, but I don't know how setting an angle for that axis would work. I have tried rotating the object, but that just results in strange motion.

On the same note, I would like my jointed object to interact with other colliders. I have enabled collision, and can push my object around with a cube with a cube collider. When I attempt to push from the underside of my jointed object, however, the object rotates unpredictably. If someone could shed some light on setting up a Configurable Joint to work like this (or show me an alternative way to achieve what I want in 3D, such as using rigidbody constraints or a different physics engine I could use), that would be very helpful.