Solid Axle
Solid axle, also called a rigid axle, connects the left and right wheel carriers so movement or alignment at one side is mechanically linked to the other.
What is rigid
The wheels share a rigid structural member, but the axle assembly still moves relative to the body through springs, dampers, and locating links. A driven solid axle may also house the differential and half shafts; a non-driven rigid axle does not.
The arrangement can provide strength and predictable wheel-to-wheel geometry, but a road input at one wheel influences the other and much of the axle assembly is unsprung mass. The term does not specify how the axle is laterally or longitudinally located.
For rigid, independent, and semi-independent layouts, see Suspension Construction. Their effects on wheel motion and body response are covered in Suspension Kinematics and Vehicle Dynamics.