SERVICE & MAINTENANCE Model 26MRT 3120892 April 11, 2000 AUSTRALIAN OFFICE EUROPEAN OFFICE CORPORATE OFFICE JLG INDUSTRIES, INC. JLG INDUSTRIES (EUROPE) JLG INDUSTRIES, INC. P.O. Box 5119 11 Bolwarra Road Port Macquarie, Australia Telephone: 065 811111 Fax: 065 810122 Kilmartin Place, Tannochside Park Uddingston, Scotland, G71 5PH Telephone: 01698 811005 Main Fax: 01698 811055 Parts Fax: 01698 811455 1 JLG Drive McConnellsburg, PA.
INTRODUCTION - MAINTENANCE SAFETY PRECAUTIONS SECTION A. INTRODUCTION - MAINTENANCE SAFETY PRECAUTIONS A.A GENERAL This section contains the general safety precautions which must be observed during maintenance of the aerial platform. It is of utmost importance that maintenance personnel pay strict attention to these warnings and precautions to avoid possible injury to themselves or others, or damage to the equipment. A maintenance program must be followed to ensure that the machine is safe to operate.
INTRODUCTION - MAINTENANCE SAFETY PRECAUTIONS REVISON LOG Original Issue - April 11, 2000 (This manual split from manual 3120844) b – JLG Sizzor – 3120892
TABLE OF CONTENTS TABLE OF CONTENTS SUBJECT - SECTION, PARAGRAPH PAGE NO. SECTION A - INTRODUCTION - MAINTENANCE SAFETY PRECAUTIONS A.A A.B A.C General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .a Hydraulic System Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .a Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TABLE OF CONTENTS LIST OF FIGURES FIGURE NO. 1-1. 1-2. 1-3. 2-1. 2-2. 2-3. 2-4. 2-5. 2-6. 2-7. 2-8. 2-9. 2-10. 2-11. 2-12. 2-13. 2-14. 2-15. 2-16. 2-17. 2-18. 2-19. 2-20. 2-21. 2-22. 2-23. 3-1. 3-2. 3-3. 3-4. 3-5. 3-6. TITLE PAGE NO. Lubrication Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4 Serial Number Locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 1 - SPECIFICATIONS SECTION 1. SPECIFICATIONS 1.1 CAPACITIES Drive Pump Closed loop piston type Hydraulic Oil Tank 56.8 liters (15.0 gallons) Hydraulic System (Including Tank) Approximately 68.1 liters (18.0 gallons) Output - 56.8 lpm (15 gpm) @ 3,000 rpm Displacement - 19.0 cm3/rev. (1.16 in.3/rev.) Lift/Steer Pump Gear type Fuel Tank Output - 11.7 lpm (3.1 gpm) @ 3,000 rpm. 29.5 liters (7.8 gallons) Displacement - 4.0 cm3/rev. (0.24 in.3/rev.). Drive Axle Steer/Drive System 6.
SECTION 1 - SPECIFICATIONS Lift 1.5 LUBRICATION Up - 34-42 seconds Hydraulic Oil Down - 31-39 seconds Table 1-1. Hydraulic Oil Platform Capacity Standard - 455 kg (1,000 lb.) HYDRAULIC SYSTEM OPERATING TEMPERATURE RANGE SAE VISCOSITY GRADE 0 to +23 degrees F (-18 to -5 degrees C) 10W 0 to +210 degrees F (-18 to +100 degrees C) 10W-20,10W-30 +50 to +210 degrees F (+10 to +100 degrees C) 20W-20 Manual Platform Extension Capacity 115 kg (250 lb.
SECTION 1 - SPECIFICATIONS Lubrication Specifications 1.6 1.8 For machine identification, a serial number plate is affixed to the machine. The plate is located on the rear center of the machine frame, just below the middle step of the ladder. In addition, if the serial number plate is damaged or missing, the machine serial number is stamped on the right front frame rail, adjacent to the sizzor arms. CYLINDER SPECIFICATIONS Table 1-2.
SECTION 1 - SPECIFICATIONS Figure 1-1. Lubrication Diagram Table 1-6.
SECTION 1 - SPECIFICATIONS Figure 1-2.
Figure 1-3.
SECTION 2 - PROCEDURES SECTION 2. PROCEDURES 2.1 This section provides information necessary to perform maintenance on the scissor lift. Descriptions, techniques and specific procedures are designed to provide the safest and most efficient maintenance for use by personnel responsible for ensuring the correct installation and operation of machine components and systems.
SECTION 2 - PROCEDURES 4. Lubricate new or used serviceable bearings before installation. When pressing a bearing into a retainer or bore, apply pressure to the outer race. If the bearing is to be installed on a shaft, apply pressure to the inner race. Gaskets Components and assemblies requiring lubrication and servicing are shown in Section 1. 2.3 Check that holes in gaskets align with openings in the mating parts.
SECTION 2 - PROCEDURES NOTE: Start-up of hydraulic system with oil temperatures below -26° C (-15° F). is not recommended. If it is necessary to start the system in a sub-zero environment, it will be necessary to heat the oil with a low density, 100VAC heater to a minimum temperature of -26° C (-15° F). 3. The only exception to the above is to drain and fill the system with Mobil DTE 11 oil or its equivalent. This will allow start up at temperatures down to -29° C (-20 ° F).
SECTION 2 - PROCEDURES Relief Valves 2.7 Main relief valves are installed at various points within the hydraulic system to protect associated systems and components against excessive pressure. Excessive pressure can be developed when a cylinder reaches its limit of travel and the flow of pressurized fluid continues from the system control. The relief valve provides an alternate path for the continuing flow from the pump, thus preventing rupture of the cylinder, hydraulic line or fitting.
SECTION 2 - PROCEDURES Cylinders w/Single Counterbalance Valves Lift Cylinder OPERATE ALL FUNCTIONS FROM GROUND CONTROL STATION ONLY. 1. Using all applicable safety precautions, activate hydraulic system. WHEN WORKING ON THE LIFT CYLINDER, RAISE THE PLATFORM COMPLETELY AND SUPPORT THE PLATFORM USING A SUITABLE OVERHEAD LIFTING DEVICE. DO NOT FULLY EXTEND LIFT CYLINDER TO END OF STROKE. RETRACT CYLINDER SLIGHTLY TO AVOID TRAPPING PRESSURE. 2.
SECTION 2 - PROCEDURES 3. If applicable, remove the cartridge-type holding valve and fittings from the cylinder port block. Discard o-rings. 8. With the barrel clamped securely, apply pressure to the rod pulling device and carefully withdraw the complete rod assembly from the cylinder barrel. 4. Place the cylinder barrel into a suitable holding fixture. Figure 2-3. Rod Support Figure 2-1. Barrel Support 5. To aid in realignment, mark cylinder head and barrel with a center punch.
SECTION 2 - PROCEDURES 15. If applicable, remove the piston spacer from the rod. 16. Remove the rod from the holding fixture. Remove the cylinder head and retainer plate from the rod. Cleaning and Inspection 1. Clean all parts thoroughly in an approved cleaning solvent. 2. Inspect the cylinder rod for scoring, tapering, ovality, or other damage. If necessary, dress rod with Scotch Brite or equivalent. Replace rod if necessary. NOTE: Install the cylinder pin into the Gar-Max bearing dry.
SECTION 2 - PROCEDURES 2. Using a soft mallet, tap a new wiper seal into the applicable cylinder head gland groove. Install a new wear ring into the applicable head gland groove. Push the head along the rod to the rod end, as applicable. 5. Carefully slide the piston spacer onto the rod. 6. If applicable, correctly place a new o-ring and backup rings in the inner piston diameter groove. 7.
SECTION 2 - PROCEDURES 10. Install the bolts into the bushing using Loctite #242. Refer to Table 2-1, Cylinder Component Torque Specifications for proper bolt torque values. 16. Secure the cylinder head gland using the washer ring and socket head bolts. Figure 2-11. Rod Assembly Installation Figure 2-10. Tapered Bushing Installation 11. Remove the cylinder rod from the holding fixture. 17.
SECTION 2 - PROCEDURES 4. Carefully lift the steer cylinder until the cylinder mounting block clears the mounting slot in the bottom of the axle, then slowly remove the cylinder from the axle and place it in a suitable work area. 2.11 STEER CYLINDER REPAIR Removal Before beginning this procedure, ensure that the parking brake is engaged and the rear wheels are chocked. Disassembly 1. Tag and disconnect the hydraulic lines to the steer cylinder, then cap the steer cylinder hydraulic lines and ports.
SECTION 2 - PROCEDURES EXTREME CARE SHOULD BE TAKEN WHEN REMOVING THE CYLINDER ROD, SPACER, AND PISTON. AVOID PULLING THE ROD OFF-CENTER, WHICH COULD CAUSE DAMAGE TO THE PISTON AND CYLINDER BARREL SURFACES. 4. With the barrel clamped securely, apply pressure to the rod pulling device and carefully withdraw the complete rod assembly from the cylinder barrel. 5. Using a suitable chain wrench, carefully remove the remaining cylinder head retainer from the opposite end of the cylinder barrel.
SECTION 2 - PROCEDURES 10. Carefully install one of the cylinder heads on one end of the cylinder rod and push the head onto the rod until it is snug against the end of the cylinder barrel. 11. Install one of the cylinder head retainers on the end of the cylinder barrel and tighten with a suitable chain wrench. Manual Adjustment 1. Park the machine on a flat, level surface and ensure the machine is level. NOTE: Ensure switch mounting bracket is level and securely attached. 12.
SECTION 2 - PROCEDURES . Figure 2-14. Tilt Switch Leveling - Voltmeter Adjustment 3. Connect the black lead of the voltmeter to ground and the red lead to the yellow wire protruding from the pot on the bottom of the sensor. 4. Adjust the leveling nuts to obtain the highest possible voltage reading. 5. Check the voltage at the trip point in all four directions. If the voltage reading is not symmetrical, repeat step 4 above. Lift Relief Adjustments 1.
SECTION 2 - PROCEDURES . Figure 2-15. Valve Components Steer Relief Adjustment 2.15 DRIVE AXLE REPAIR 1. Install a pressure gauge at gauge port MP, located on the lower right side of the valve body. The port is identified by a stamping on the valve body. 2. Activate the Steer Right function and check Steer pressure. If necessary, adjust Steer pressure to 103 bar (1500 psi). 3. Activate the Steer Left function and check Steer pressure. If necessary, adjust Steer pressure to 103 bar (1500 psi). 4.
SECTION 2 - PROCEDURES Axle Installation 1. Move the drive axle to its proper position beneath the machine frame, then properly support the axle. Install the four u-bolts and secure them in place with the eight locknuts and washers. When drive axle is properly secured, remove the axle supports. 2. Install the wheel and tire assemblies on the axle and secure each assembly in place with five wheel nuts. 3. Remove the supports from the rear of the machine and remove the chocks from the front wheels.
SECTION 2 - PROCEDURES Figure 2-16.
SECTION 2 - PROCEDURES Cleaning and Inspection 1. Use a standard metal cleaning solvent to clean out the bearing bore in the housing. Wipe this area clean, making sure it is free from dirt or any other contamination that might be present. 2. Inspect the machined surfaces of the axle shaft, such as the seal and bearing diameters. Clean the axle shaft and remove all nicks or burrs. 3. If the wheel bearing is to be replaced, proceed to Installation.
SECTION 2 - PROCEDURES 14. Assemble the bearing cup into the bearing bore of the axle housing. Ensure the cup backface is seated firmly against the bearing seat of the housing. 15. Install the axle shaft into the axle housing, taking care not to damage the seal lip and bearing rollers. 16. Line up the holes of the axle shaft retainer with the mounting holes in the end of the axle housing, then push the axle shaft into the housing as far as it will go. 17.
SECTION 2 - PROCEDURES NOTE: On the spline end of the pinion, there are bearing preload shims. These shims may stick to the bearing - pinion - or even fall out. The shims are to be collected and kept together since they will be used later in assembly. Try not to damage the shims. If the shims are mutilated, replace them with new ones. 13. Pull out the pinion seal using a slide hammer (Dana part no. D-131) and discard the seal. Install a new seal at the time of assembly.
SECTION 2 - PROCEDURES (0.003 in) more shims be added than if the pinion were etched ”0". By adding 0.076 mm (0.003 in) shims, the mounting distance of the pinion was decreased to 66.599 mm (2.622 in), which is just what a -3 etching indicated. 10. If the old ring and pinion set are to be reused, measure the old shim pack and build a new shim pack to the same dimension. If a baffle is in the axle assembly, it is considered as part of the shim pack.
SECTION 2 - PROCEDURES 5. Assemble the remaining shims of the total shim pack to the opposite side of the differential case. Add an additional 0.381 mm (0.015 in) of shims on this side to compensate for the differential bearing preload. Assemble the differential bearing using the same tools used in step 4. 6. Install a spreader and indicator and carefully spread the carrier housing, but DO NOT spread the carrier over 0.381 mm (0.015 in). Remove the indicator. 7.
SECTION 2 - PROCEDURES Ring Gear and Pinion Tooth Pattern Interpretation The TOE of the gear tooth is the portion of the tooth surface at the end towards the center. The HEEL of the gear tooth is the surface of the top of the tooth. Every gear has a characteristic pattern. The illustrations in Figure 2-18 show typical patterns only, and explain how patterns shift as gear location is changed. When making pinion position changes, shims should be changed in the range of 0.051 mm (0.002 in) to 0.102 mm (0.
SECTION 2 - PROCEDURES Figure 2-19. Ring Gear Pattern Interpretation Check the ring gear and pinion tooth pattern as follows: • Thicker pinion position shim with the backlash constant moves the pinion closer to the ring gear. • Paint the ring gear teeth with a marking compound to both the drive and coast side. Drive pattern moves deeper on the tooth (flank contact) and slightly toward the toe.
SECTION 2 - PROCEDURES 2. Tap the female end of the spline shaft assembly and spring plate with a soft mallet to separate the cover from the spring plate. If the sections will not separate, carefully pry the sections apart with a screwdriver. 3. Remove the retaining ring from the spline shaft assembly. 4. Remove the spline shaft assembly from the cover by tapping the male end of the spline shaft assembly with a soft mallet. 5.
SECTION 2 - PROCEDURES Figure 2-20.
SECTION 2 - PROCEDURES ature. Adjust the IDLE screw CW (higher) or CCW (lower) until IDLE speed is 1200 RPM. IF HYDROSTATIC BENCH TESTING IS PERFORMED ON THE BRAKE ASSEMBLY, RELEASE PRESSURE SHOULD NOT EXCEED 69 BAR (1,000 PSI) UNLESS FOUR ADDITIONAL BOLTS ARE USED FOR SUPPLEMENTAL CLAMPING. 2.17 THROTTLE CHECKS AND ADJUSTMENTS 3. Position toggle switch to MID engine.
SECTION 2 - PROCEDURES Figure 2-21.
SECTION 2 - PROCEDURES Figure 2-22.
SECTION 2 - PROCEDURES The valve driver card potentiometer adjustments are as follows: P1 - DRIVE FWD ACCEL (A RAMP UP) P2 - DRIVE FWD DECEL (A RAMP DOWN) NOTE: If the horsepower card’s voltage does not change, then the card is not receiving the RPM signal, the engine speed is not correct, or the card is bad. Replace the horsepower card if necessary. DO NOT ATTEMPT TO ADJUST THE HORSEPOWER CARD. P3 - DRIVE FWD HIGH (A MAXIMUM) 5.
SECTION 2 - PROCEDURES 13. Turn P8, drive reverse low, clockwise until the wheels just start to move. The ammeter should read about 0.4 Amps or 400 mA. This value is approximate, the reading will be slightly different from one machine to another. NOTE: Adjusting the low setting affects the high. Adjusting the high setting does not affect the low. If you have to re-adjust the low after the high is set, you must recheck the high, the decel, and the accel settings. 14.
SECTION 2 - PROCEDURES The inspection and maintenance code numbers are as follows: 2.20 PREVENTIVE MAINTENANCE AND INSPECTION SCHEDULE 1. Check for proper and secure installation. The preventive maintenance and inspection checks are listed and defined in the following table. This table is divided into two basic parts, the “AREA” to be inspected and the “INTERVAL” at which the inspection is to take place.
SECTION 2 - PROCEDURES Table 2-3. Preventive Maintenance and Safety Inspection AREA INTERVAL 10Hours (Daily) 50 Hours (Weekly) 200 Hours (Monthly) 500 Hours (3 Month) 1000 Hours (6 Month) PLATFORM 1. Controller 1,11 2. Switches 1,11 3. Placards and Decals 1,2 4. Control Tags 1,2 5. Hoses and Cables 4,8 6. Wear Pads 8 7. Handrails and Chains 1,4 CHASSIS 1. Engine Oil 3 5 2. Battery 3 5 3. Air Cleaner 1 14 4. Exhaust System 1 1,5 5. Engine Mounts 1 6.
SECTION 3 - TROUBLESHOOTING SECTION 3. TROUBLESHOOTING 3.1 GENERAL 3.3 This section contains troubleshooting information to be used for locating and correcting most of the operating problems which may develop in the aerial platform. If a problem should develop which is not presented in this section or which is not corrected by listed corrective actions, technically qualified guidance should be obtained before proceeding with any maintenance. 3.
SECTION 3 - TROUBLESHOOTING . Table 3-1. Elevation System Troubleshooting TROUBLE PROBABLE CAUSE REMEDY Platform Elevation System No Response to LIft Control Enable switch not activated. Activate enable switch. Lift control switch not activated within three seconds after enable switch is activated. Activate enable switch, then activate lift control switch within three seconds. Enable circuit not functioning properly. Replace enable circuit card. Lift control switch inoperative.
SECTION 3 - TROUBLESHOOTING Table 3-1. Elevation System Troubleshooting TROUBLE PROBABLE CAUSE REMEDY Platform raises and lowers erratically Hydraulic system oil low. Replenish oil as necessary. Restricted or broken hydraulic line or fitting. Clean, repair or replace line. Counterbalance valve on lift cyl. improprely adjusted or not functioning properly. Replace valve. Control valve not functioning properly. Repair or replace valve. Worn seals in lift cylinder. Replace seals.
SECTION 3 - TROUBLESHOOTING Table 3-2. Chassis Troubleshooting TROUBLE PROBABLE CAUSE REMEDY Drive System No response to drive controller Enable switch not activated. . Activate enable switch Controller not activated within three seconds after enable switch is activated. Activate enable switch, then activate drive controller within three seconds. Enable circuit not functioning properly. Replace enable circuit card. Hydraulic system oil low. Replenish oil as necessary.
SECTION 3 - TROUBLESHOOTING Table 3-2. Chassis Troubleshooting TROUBLE PROBABLE CAUSE REMEDY High-Speed Drive function does not operate Loose or damaged wiring between drive controller and High Speed switch. Ensure proper connection of wires. Using suitable test meter, perform continuity test on wiring between switches. Repair or replace wires as necessary. Defective high speed control switch. Replace high speed control switch. Loose or damaged wiring in control box wire harness.
SECTION 3 - TROUBLESHOOTING Table 3-2. Chassis Troubleshooting TROUBLE PROBABLE CAUSE REMEDY Machine hard to steer or steering is erratic (cont.) Lack of lubrication on steer components. Lubricate steer components in accordance with Lubrication Chart. Restricted crossover relief valve. Clean or replace valve. Steer system pressure low. Adjust pressure. Bent steering linkage. Repair or replace linkage as required. Hydraulic pump not functioning properly. Repair or replace valve.
SECTION 3 - TROUBLESHOOTING Table 3-3. Hydraulic System Troubleshooting TROUBLE PROBABLE CAUSE REMEDY Hydraulic System - General Hydralic Pump Noisy Air bubbles in oil. (Reservoir too low.) Replenish oil as necessary. Oil filter dirty. Clean and/or replace filter as necessary. Pump cavitating. (Vacuum in pump due to oil starvation) Oil in reservoir low . Replenish oil as necessary. Restricted reservoir air vent. Clean vent. Oil viscosity too high. Drain system and replace with recommended oil.
SECTION 3 - TROUBLESHOOTING Table 3-4. Electrical System Troubleshooting TROUBLE PROBABLE CAUSE REMEDY Hand Controller Valve will not function when handle is moved in either direction. Enable switch not activated. Activate enable switch. Controller not activated within three seconds after enable switch is activated. Activate enable switch, then activate controller within three seconds. Enable circuit not functioning properly. Replace enable circuit card. No electrical power to handle.
SECTION 3 - TROUBLESHOOTING Table 3-4. Electrical System Troubleshooting TROUBLE PROBABLE CAUSE REMEDY No voltage present at applicable control valve coil. Check applicable wire for proper connection at terminal strip, valve harness plug pin, valve harness receptacle pin and engine start relay. Using suitable test meter, perform continuity test on wire. Repair or replace wire or harness as necessary. No response to a function control switch (cont.
SECTION 3 - TROUBLESHOOTING Figure 3-1.
SECTION 3 - TROUBLESHOOTING 1870102 C Figure 3-2.
SECTION 3 - TROUBLESHOOTING Figure 3-3.
SECTION 3 - TROUBLESHOOTING 1870103 C Figure 3-4.
SECTION 3 - TROUBLESHOOTING Figure 3-5.
SECTION 3 - TROUBLESHOOTING 1282590 L Figure 3-6.
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Corporate Office JLG Industries, Inc. 1 JLG Drive McConnellsburg PA. 17233-9533 USA Phone: (717) 485-5161 Customer Support Toll Free: (877) 554-5438 Fax: (717) 485-6417 JLG Worldwide Locations JLG Industries (Australia) P.O. Box 5119 11 Bolwarra Road Port Macquarie N.S.W.