A PTO (Power Take Off) is a mechanism usually seated on the flywheel housing, which transfers power from the driveline (engine) to a secondary application.
In most cases, this power transfer applies to a secondary shaft that drives a hydraulic pump, generator, air compressor, pneumatic blower, or vacuum pump. Power take offs allow mobile crushing plants, road milling machines, and other vehicles to perform secondary functions without the need for an additional engine to power them.
Overtime the outputs for these secondary applications wear and need refurbishing with new shaft, bearings etc. The skill/challenge is to reclaim these bores accurately to the driveline input (single datum).
The housing is returned to the client with refurbished (reclaimed) bores ready for fitting of bearings and shafts.