JLG 400S: More Than 30 Years in the Making

JLG Industries, McConnellsburg, Pa., has built more 40-foot boom lifts for longer than any other company. In total, the company has delivered in excess of 40,000 40-foot gas/propane or diesel-powered booms.

The Model 400S is actually JLG's fifth-generation 40-foot boom, and along with sister machine 460SJ, which features a 6-foot articulating jib, they make up a powerful one-two product punch. The 400S demonstrated at the Boom Lift Showcase featured four-wheel drive and an optional oscillating axle, a feature the company pioneered back in 1981.

The 400S is a quick operating machine, posting a swift 4.5-mph travel speed and equally impressive lift and rotation speeds. JLG is the only manufacturer to offer a dual-capacity load chart, which allows 500 pounds of unlimited capacity and 1,000 pounds of limited capacity. A 750-pound unlimited capacity option is available as well. Platform rotation of 180 degrees is standard.

The 400S utilizes a simple two-section boom and a basic inverted-style open steel power track. A zinc-plated power track is available for coastal areas at an additional cost. Pivot pins are all nickel-plated.

Located on the side of the platform is JLG's hallmark inward swinging entry gate. Multi-function controls are set wider apart to allow easier selection and limit accidental actuation by gloved hands. Information like fuel level and engine status are also present here. Other platform features include a roto-molded workstation, which provides a good place to store small loose items. There is also a pair of integral cup holders.

JLG's ADE Advanced Design Electronics is incorporated into every facet of the machine's controls. This all-encompassing microprocessor-based operating system is the nerve center of the machine. A single CPU controls everything from engine function and hydraulic controls, as well as monitors the safety system of the machine. ADE also has a sophisticated self diagnostic system accessed via a small hand-held analyzer. Technicians use the information presented in the LED readout and can refer to both print and online service manuals.

JLG is the only producer that does not have a boom interlock. When the boom is off-level more than 5, the operator is visually and audibly warned of this potential hazard, but operation is not suspended. The drive system is an efficient closed-loop hydrostatic drive supplied by Sauer Sundstrand. Power is distributed equally through a pair of flow dividers. Bosch Rexroth proportional valves are commanded by controls produced by OEM Controls. Fairfield torque hubs are utilized not only to provide superior power to the drive wheels but also for the rotation of the superstructure. This planetary system has an integral multi-disk brake.

The 400S's engine and virtually every other component are mounted on the side of the machine under fiberglass hoods. Currently, owners can select one of three engine options, including a four-cylinder, 82-hp GM Vortec water-cooled gas/propane, a 50-hp Cat water-cooled, or the 49-hp Perkins 404C-22, which was installed in the Showcase machine. For improved serviceability, the engine pivots out. The combination of sound-baffling material fitted around the ABS cover helps hold the engine noise to 70 dbi. JLG has eliminated all but one grease point on the machine.

As with all JLG products, the 400S can be fitted with any one of the Workstation in the Sky work platform tools. In addition to the 7,500-watt SkyPower generator shown on this unit, other options include the 250-amp SkyWelder welding packages complete with welding leads strung into the boom, and the SkyCutter with an on-board Miller Spectrum 375 CutMate. With the number of unique features and optional accessories available on the 400S, it's no wonder that JLG continues to be a leader in 40-foot boom production.

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guy ramsey

Guy Ramsey

Guy Ramsey is president of Maximum Capacity Media, publisher of Crane & Rigging Hot Line, Lift and Access, Industrial Lift & Hoist, and Lift & Hoist International.