The Jumbo Mould Shaft is a guide shaft that aligns the mould bracket with the carrier plate for the Jumbo MK2, Jumbo MK3 and Hyperstat brick machines. It is a critical component to ensure the stamper fits into the mould box, once calibrated. Two shaft nuts at the top are tightened against eachother to create a stopping mechanism that will determine the height of the brick product being made. Midway along the shaft is an indentation that allows the carrier plate to lock into place through the use of a cap screw. NOTE: If this cap screw is loose, it will wear away the groove and become unreliable for lifting the stamper uniformly on both sides - always check this screw periodically. 
 
The wear and tear is primarily from the movement through the bottom sleeve; but also through loose carrier plate cap screws. Critical breaks occur at the mid level from machine usage where vibration is far in excess of recommended requirements to achieve sufficient brick density.
 
The shaft steel is a compromise of abrasive wear (from sleeves) and tensile strength (for vibration and torque forces) but is the strongest part of the Jumbo series brickmaking machine range.
 
Add LM grease to reduce friction forces and prolong the lifespan of this part.