Dressta recently expanded its wheel-loader lineup with the addition of the 555C Extra wheel loader. The 555C Extra features a new turbocharged diesel engine, single-phase torque converter, electrically controlled transmission, hydrostatic steering, and single-lever hydraulic controls.
Power is provided by a new turbocharged inline six-cylinder Cummins QSM11 engine that provides 319 hp (238 kW) at 2100 rpm and 1235 lb·ft (1674 N·m) at 1400 rpm. The 10.8-L engine is certified to meet U.S. EPA Tier 3 emissions regulations.
Dressta upgraded the 555C’s hydraulic system and added a new cooling module to allow for a variable-speed cooling fan on the 555C Extra. At minimum usage, extra cooling provided by the fan allows an output of 330 hp (246 kW).
Engine power is matched to the load by a single-phase, single-stage torque converter with a 2.9:1 stall ratio. The 555C Extra’s electrically controlled full power shift, countershaft transmission is driven by a double universal joint from the torque converter to provide smooth modulation on all shifts and a comfortable ride for the operator. The four-speed countershaft transmission allows gears to mesh continuously, so adjustments are effectively eliminated.
This machine’s articulating frame provides articulation of 40° to the right or left and a tight 21.3-ft (6.5-m) turning radius. The 5264-lb (2388-kg) counterweight is standard. Heavy-duty axles incorporate full-floating axle shafts and a planetary final drive.
Multiple wet-disc brakes are arranged in two independent hydraulic brake circuits—one in front and one at the rear. Brakes are completely sealed and force-cooled to reduce downtime and improve safety and reliability. Hydrostatic steering provides smooth control at any engine speed, and directional transmission and speed shift are controlled using levers mounted within the operator’s reach.
Z-bar linkage design features a single-bucket cylinder that puts less weight on the front, reduces the number of components, and minimizes the number of wear and maintenance points. Loader linkage pins are sealed to keep out abrasive dust and grit, helping to extend lubrication intervals as well as pin-bushing life, and boom cylinders are mounted outside the front frame for easy access and maintenance.
Dressta’s newest loader can be equipped with buckets ranging from 5.5 to 11.0 yd3 (4.2 to 8.4 m3) and has an approximate operating mass of up to 66,380 lb (30,110 kg). The cab offers high visibility in all directions and is equipped with a full complement of gauges and warning lights that allow the operator to monitor current operating conditions.
The 555C Extra is part of Dressta’s complete wheel loader lineup, which includes the 515G, 520G, 530E, and 560E.