Factory Direct Sales ZJ40/2250CZ Truck-Mounted Drilling Rig for Oil Well ZJ40 truck mounted drilling rig is the biggest light duty self-propelled truck-mounted drilling equipment. Several patent technologies and new technologies are used in the unit. Mature and reliable compound system for double engine is used. Compound gear box with unique design is of reliable driving performance and reasonable load distribution. Auxiliary brake of draw work is air control water cooling