First manufactured and marketed by Gradall before it was acquired by JLG Industries, McConnellsburg, Pa., the G6-42P was recently rebranded as JLG and integrated into the JLG-brand telehandler line. The G6-42P is now one of 11 machines in the JLG line, which does not include the SkyTrak and Lull machines. Although the unit shares many of the same design philosophies as the JLG G6-42A, the G6-42P features a construction that is truly unique to the industry. The machine’s distinctive 90° pivot-steering axle configuration, along with its bright blue color, set it apart.
The rear-pivot design keeps the outside turning radius at only 171 inches and allows for the load to be carried inside the turning circle. While in the past the complex axle design and additional service points led to the possibility of premature failure, JLG has installed a centralized grease point, and the load-bearing surface now has an O-ring seal around the bottom to limit the intrusion of dirt and grit.
The G6-42P has two- and four-wheel drive modes. The front axle on the G6-42P is a rigid, high-bias limited slip differential design that is supplied by Carraro. Independent hydraulic drive motors coupled with Fairfield torque hubs power each rear wheel. On the floorboard of the cab, a separate traction control pedal that sits between the accelerator and the brake is used for differential axle lock. When depressed, in conjunction with the accelerator, this traction lock splits the oil flow between the front and rear axles. A separate set of relief valves protects the rear-drive motors from any pressure spikes.
The Rexroth-supplied hydrostatic transmission requires no selection of gears on the operator’s part; it is simple forward and reverse column-mounted shift. Maximum operating pressure is 6,300 psi, and the transmission comes online when the 99-hp John Deere 4045T turbocharged diesel engine is turning at about 1,100 rpm.
Another feature of the hydrostatic drive is the ability to de-stroke the pump, which is accomplished by depressing the brake pedal halfway. De-stroking the pump allows the operator to inch, or feather, the drive and/or brake with the use of one pedal. It also allows the drive speed to be regulated independently from the engine speed, which will allow auxiliary flow to be kept at maximum levels.
Control options on the G6-42P are similar to the G6-42A. Lift-lower/telescope and frame sway/fork tilt are operated by two right-hand controls while auxiliary hydraulics are controlled by a standard left-hand joystick on the dash. The design allows the operator to run lift/lower and fork tilt in the right hand and control the auxiliary at the same time with the left.
The G6-42P has a fairly long 130-inch wheelbase and a low center of gravity, which translates into greater lifting capabilities and added stability when carrying a load over rough terrain. Without outriggers, the machine lifts 6,000 pounds to the maximum 42-foot lift height and 1,300 pounds to its full forward reach of 29 feet. Primarily a pick-and-carry machine, the unit offers great visibility to the side and rear when a load is in the carry position. Good visibility is due in part to the low side-mounted engine and an efficient boom support structure design.
The fuel fill is located behind the cab while the hydraulic fill is on other side of the machine, which helps to eliminate accidental contamination. Under the hood, the engine is mounted so all service points, including the starter, are mounted in clear view. The battery is positioned at the front to easily jump start the machine.
The G6-42P uses the same JLG coupling unit that is standard on JLG, Lull, and SkyTrak machines, allowing operators with any of the three product lines to share attachments. The Equipment Showcase unit was shipped with a 15-foot truss boom, but it is also available with a variety of standard, side-tilt, and swing carriages; pallet, lumber, and cubing forks; material and grapple buckets; a fork-mounted work platform; and lifting hook.
Lift and Access Perspective: In a sea of conventional steering telehandlers, the G6-42P stands out for its capability to maneuver within areas no wider than its overall stowed length. Now that JLG has addressed the issue of rear axle service life, there really isn’t much out of the normal to be concerned with on the service front. Although rear visibility is enhanced by the minimal design of the boom uprights, it is somewhat limited to the immediate right of the operator by the size of the side-mounted engine pods’ cowling. Although side-mounted pods make life easier on service techs, there is some trade off. The challenge is to keep the operator’s seat low to allow for easier access, but not so low as to limit the line of sight over the hood. JLG has tried to strike a balance on this, and it really gets down to a personal choice.