End caps plus cradle tube plus shims have a fixed width "A", adjustable with shims.

The assembly of central rubbers, spacers and collars has a fixed (non-adjustable) distance "B" between the collar inside faces when the nuts are tightened to 25 ft/lbs. NO MORE! to avoid collapse of the internal parts.

The PTFE washers (item 44) provide a low-friction interface between end-caps and collars.

Using shims as required "A" should ideally measure .005" -.010" less than "B" so that the cradle is "isolated" from the rest of the frame, and free to move on the rubbers in a vertical plane.

It is important that the cradle tube ends are free of paint and burrs so that the end-caps turn easily when fully home.

All shims can go on the same side, but if thin ones are required place these inside the end-cap first. A thick one against the cradle tube will reduce any chance of fretting.

It is easiest to adjust rear shimming on the right side where access is better.

The same principle applies to the front mounting, though it may be found easier to adjust shimming with the complete assembly on the workbench, i.e. removed from the motorcycle.