The Watts linkage can be either “axle mounted” or “chassis mounted”. This refers to the location of the Watts lever pivot axis.

Axle mounted Watts link pivot.

There are five chassis mounting points, one for the torque arm slider bearing, one for each trailing link, one for each Watts link.

There are six axle mounting points, two for the torque arm slider, one of which is reference point to determine the slider axis, one for each trailing link, and two for the Watts pivot, one of which is reference point to determine the pivot axis.

Chassis mounted Watts link pivot.

There are five chassis mounting points, one for the torque arm slider bearing, one for each trailing link, and two for the Watts pivot, one of which is reference point to determine the pivot axis.

There are six axle mounting points, two for the torque arm slider, one of which is reference point to determine the slider axis, one for each trailing link, one for each Watts link.