Another common failure is a broken solder joint holding the spindle to the speed cup.
Brian has sourced a secret supply of new speed cups that allow his team to make reliable, permanent repairs.
All components must be reassembled in precisely the right order or the unit will not work properly and may, in fact, cause damage to newly-replaced parts.
Pinpoint lubrication with a light machine oil helps prevent the "speedometer howl" so common in cars of the 50's and 60's.
The field plate and speed cup are mounted to the frame, forming the foundation of the reassembled speedometer head assembly.
Installation of the third worm is a precision step in the process.