Caterpillar 12H Motor Grader
The 12H has a 3306 naturally aspirated or turbocharged engine producing 140 flywheel horsepower (FWHP). It has an eight speeds forward, six reverse direct drive powershift transmission with electronic control. It comes standard with adjusted blade positioning, PPPC hydraulic system, and modified operator station. It is available with integrated engine compartment doors and a contour seat.
The 12H was manufactured in the USA, with a 2LR, 4XM, or 5ZM serial number prefix; in Australia, with a 2WR prefix; and in Brazil, with a 2GS, 4ER, or 8MN prefix.
The 2LR and 2GS units have turbocharged engines.
In 1996 and 1997 Caterpillar added extended life coolant to the USA units, beginning with 2LR0029, 4XM00941, and 5ZM00288.
Production of 2LR ended in 1996.
In 1997 Cat added radiator cleanout access covers and new battery boxes, modified the fuel-sending unit, and adjusted the drawbar to improve visibility, beginning with 2WR00566, 2GS00300, 4ER00400, 8MN00460, 4XM01048, and 5ZM00288. At the same time the 2WR, 2GS, 8MN, and 4XM units received an emission regulated turbocharged engine, and had their rated speed changed from 2,000 to 1,900 revolutions per minute (RPM).
Also in 1997, the oil filter was made more accessible and an optional 12-volt power port was added, beginning with 2WR00642, 2GS00360, 4ER00500, 8MN00500, 4XM01396, and 5ZM00288. At the same time the 2GS, 4ER, 8MN, 4XM, and 5ZM units received scheduled oil sampling ports and a circle drive slip clutch.
In 1998, a four-legged spider gear replaced the three-legged spider in the differential along with the single piece-bearing cap to improve the service life of the differential, beginning with 2WR00727, 2GS00379, 4ER00549, 8MN00624, 4XM01869, and 5ZM00298.
Production of 5ZM ended in 1998.
In 1999 the differential spider gear bearing material was changed from aluminum bronze to manganese bronze to decrease the material transfer from the bearing to the spider leg, beginning with 2WR00829, 2GS00402, 4ER00590, 8MN00707, and 4XM002240.
In 2000 the lower ripper link was modified to improve the service life, beginning with 2GS00453, 4ER00632, 8MN00738, and 4XM02507.
In 2001, new final drive sun gear shafts were added to improve service life, beginning with 2WR00923, 2GS00481, 4ER00655, 8MN00753, and 4XM02643. The fan spider was modified, beginning with 2WR00930, 2GS00487, 4ER00659, 8MN00753, and 4XM02622.
In 2003 Caterpillar introduced new units in the USA, with an AMZ prefix; in Australia, with a 125 prefix; and in Brazil, with a CBK prefix.
The new American and Brazilian 12H units have C9 electronic engines with air-to-air aftercooling (ATAAC) producing 145 FWHP. They come standard with a serpetine belt with automatic tensioner, a fuel water separator, enhanced vehicle styling, 500-hour oil change interval, modified remote engine oil drain, on-demand hydraulically driven “pull” fan, inside mounted air dryer, ground level fueling, left hand side centralized service access, sample ports on all systems, ground level coolant check, automotive-style fuses, electronic throttle, increased cab air flow to the windshield, electronic transmission directional solenoids, and LED stop/turn lights. They are also available with three-level variable horsepower.
The new Australian unit has a Cat C9 hydraulic/electric unit injector (HEUI), four-valve, ATAAC engine. It comes standard with electronic clutch pressure control (ECPC) transmission and electronic controls.
In 2003 steering accumulators were added, beginning with AMZ00360.
In 2004 a new final drive was added and preload was adjusted, beginning with 2WR01260, 2GS00667, 4ER00862, 8MN0945, and 4XM03277.
In 2005 and 2006 a larger transmission filter was added, beginning with CBK00953 and AMZ00822.
In 2006 Cat modified the circle pinion, beginning with 4ER01096, CBK00965, and AMZ00776. An AccuGrade ready option became available, beginning with CBK00992 and AMZ00706.
Based on data from the sales database of Ritchie Bros. Auctioneers, it is estimated that more than 5,700 Caterpillar 12H motor graders have been produced.
|Total = 5,767|