SB2102E01 Jan.2004 Specifications Systems Operation Testing & Adjusting Lift Trucks Power Train D20S-3, D25S-3, D30S-3, D32S-3 D20S-3(B3.3), D25S-3(B3.3), D30S-3(B3.3), D32S-3(B3.3), D33S-3(B3.
Important Safety Information Most accidents involving product operation, maintenance and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs. A person must be alert to potential hazards. This person should also have the necessary training, skills and tools to perform these functions properly.
Index Specifications Drive Axle Mounting Group....................................... 14 Drive Tire Installation ................................................ 12 Drive Wheel Installation ............................................ 13 Final Drives And Wheels........................................... 11 Forward / Reverse Clutch Elements ...........................6 Forward And Reverse Control Group .........................5 Tightening Torques .....................................................
Forward And Reverse Control Group Specifications Torque Converter (1) Torque for screws (four) that hold clamp to hand control switch………..3.4 to 3.9 N·m (30 to 35 lb·in) (2) Torque for bolts (two) that hold clamp to steering column……………….2.8 to 3.4 N·m (25 to 30 lb·in) Apply a bead of LOCTITE NO.242 Sealant to inner radius of the clamp, prior to assembly. (1) Torque for six bolts that hold torque converter drive plate to the flywheel …………………………………...
Forward / Reverse Clutch Elements C 1.4 minimum B A Snap ring c) Piston return spring Length under test force……………...29 mm (1.14 in) Test force………………..970.9 ±50 N (218.4 ± 11 lb) Free length after test(nominal) ..…56.6 mm (2.23 in) Outside diameter…………………..…95 mm (3.74 in) a) Outer clutch Disc d) Clearance between piston and pressure disc (disc pack pushed against snap ring, piston fully retracted in gear)………………..1.4 mm (0.
Valve Block Elements (On top of transmission) Tighten to 50±7 N·m (37±5 Ib·ft) Tighten to 0.6 N·m (0.44 Ib·ft) min Tighten to 25±4 N·m (18.5±3 Ib·ft) Tighten to 5±1 N·m (3.7±1 Ib·ft) SECTION A-A Tighten to 5.5±1.5 N·m (4±1 Ib·ft) A C Tighten to 50±5 N·m (37±3.7 Ib·ft) D,E Tighten to 50±7 N·m (37±5 Ib·ft) B Tighten to 50±7 N·m (37±5 Ib·ft) A) Spring Length under test force……..…...22.5 mm (0.89 in) Test force………………,,,….42 ± 3.4 N (9.4±0.8 lb) Free length after test(nominal)...34.65 mm (1.
Valve Spring in Transmission Bearing Plate Tighten to 45 N·m (33.2 Ib·ft) Converter Inlet Valve A 2-Springs Tighten to 45 N·m (33.2 Ib·ft) Converter Outlet Valve A) Spring Length under test force…………….30 mm (1.18 in) Test force…………….......18.1 ± 1.8 N (4.07±0.4 lb) Free length after test(nominal)...43.25 mm (1.70 in) Outside diameter…………………10.7 mm (0.
Power Train 9 U-joint Bolt 70 N m (51.7 Ib ft) PTO Pump Bolt 30 N m (22.1 Ib ft) Axle Lube Pump Bolt 12 N m (8.9 Ib ft) Bearing Shims See Instructions Bearing Shims Housing Bolt 55 N m Plug 50 N m (36.9 Ib ft) (40.6 Ib ft) Housing Bolt 55 N m (4.6 Ib ft) Bolt 40 N m (29.5 Ib ft) Bearing Shims See Instructions Flexplate Bolt 55 N m (40.6 Ib ft) Pump Housing Bolt 32 N m (23.6 Ib ft) Bearing Plate Bolt 55 N m (40.6 Ib ft) Bolt 20 N m (14.
Power Train 10 Bolt 28 N m (20.7 Ib ft) Apply Loctite 242 to thread Bolt 115 N m (84.9 Ib ft) Apply Loctite 242 to thread Bolt 115 N m (84.9 Ib ft) Apply Loctite 242 to thread _8 N m (59.0+ _5.9 Ib ft) Bolt 80+ Adjust to (Slightly Oiled) 19.6 N m (14.5 Ib ft) drag (See Instructions) Shims (See Instructions) Grease Bearing Bolt 285 N m (210.3 Ib ft) With Molycote BR2 Apply Loctite 242 to thread Nut 50 N m (36.9 Ib ft) (See Instructions) Spacer and Shims (See Instructions) Nut 150 N m (110.
Final Drives And Wheels D,G Model Trucks Dual Drive wheels shown GC Model Trucks 1 1 2 2 3 4 3 5 4 6 5 Oil Cooled Disc Brake Type (1) Apply LOCTITE NO.242 Thread Lock to threads of spindle bolts. Torque for bolts that hold spindle to drive axle housing………………..115 ± 14 N∙m (85 ± 10 lb∙ft) Oil Cooled Disc Brake Type (1) Apply LOCTITE NO.242 Thread Lock to threads of spindle bolts. Torque for bolts that hold spindle to drive axle housing……………..
Drive Tire Installation Y GC30, GC32 Models-Wide Axle GC20, GC25 Models WARNING The drive tire must be installed as shown below. Failure to do so will decrease the stability of the truck, and can cause injury to the operator. GC20, GC25 Models Install the tire so that the edge of the tire is even with the outside edge of the wheel. GC30, GC32 Models Narrow Axle : GC30, GC32 Models-Narrow Axle Install the tire so there is distance (X) between the edge of the tire and the inside edge of the wheel.
Drive Wheel Installation D,G Model Trucks GC Model Trucks 1 1 (1) Tighten wheel mounting bolts to a torque of ……………………….270 ± 25 N∙m (200 ± 20 lb∙ft) Power Train (1) Tighten wheel mounting bolts to a torque of ……………………….644 ± 34 N∙m (470 ± 25 lb∙ft) Use a crisscross procedure to tighten nuts.
Drive Axle Mounting Group 1 Special shoulder Bolt Chassis Standard Bolt Drive Axle Housing 2 (1) Torque for two nuts that hold the axle to the chassis……………..…488 ± 27 N∙m (360 ± 20 lb∙ft) (2) Torque for two nuts that hold the axle to the chassis………...…..….
Systems Operation General Information 2 3 4 1 Power Flow (1) Drive axle. (2) U-joint. (3) Transmission. (4) Engine. The basic components of the power train are engine (4), Transmission (3), U-Joint(2), Drive axle(1) and the final drives and wheels. Power from yoke of drive axle is sent through a spiral bevel gear set to the differential. The differential sends power out through the axles to the final drives and wheels. Two axle shafts connect the differential to two final drives.
Transmission and Drive Axle The torque converter has four main parts : housing (4), impeller(pump) (3), turbine(1) and stator(2). The housing is connected to the engine flywheel through a flexplate. Impeller (3) and housing (4) are welded together and turn with the engine flywheel at engine speed and in the direction of engine rotation. Turbine (1) turns the transmission input shaft. Stator (2) is installed stationary on stator support (5) by a freewheel clutch that allows one way rotation of the stator.
Transmission 11 3 9A 10 2 1 4 9 16 5A 6 14 5 15 14A 8 7 13 12 (1) TC Housing. (2) TM Bearing Plate. (3) TM Housing. (4) Torque Converter. (5) Input Shaft. (5A)Input Shaft Gear. (6) Oil Pump. (7) Forward Gear. (8) Forward Clutch. (9) Reverse Shaft. (9A) Reverse Shaft Gear. (10) Reverse Clutch. (11) Reverse gear. (12) Output gear. (13) U-joint. (14) Quill Shaft. (14A) Coupling. (15) PTO Pump. (16) Axle Lubrication Pump.
Transmission Power Flow Forward : With the transmission control in forward, which will pressurize the forward clutch (8), power will flow from the engine through the torque converter to drive the oil pump (6) and the input shaft (5), also the quill shaft (14). Since the forward clutch (8) locks the forward gear (7) to the input shaft, the power flows through the forward clutch (8), the forward gear (7) to output gear (12) which is in mesh with the forward gear.
Transmission Power Flow Reverse : With the transmission controls in reverse, which will pressurize the reverse clutch (10), power will flow from the engine through the torque converter to drive the oil pump (6) and the input shaft (5) also the quill shaft (14). Since the reverse clutch (10) is closed, power will flow through input shaft gear (5A) which is in mesh and drives reverse shaft gear (9A) and reverse shaft (9).
Transmission Lubrication Schematic : Oil Cooler TC Relieve Valve Oil for lubrication of the clutch shaft bearings and cooling the clutch discs and plates comes from the outlet passage of oil cooler. Lubrication oil is also splashed inside the transmission case. Lubrication oil is especially important for cooling the clutches. High temperatures can be caused during repeated shifting of the lift truck.
Drive Axle 88 10 10 99 3 77 66 11 11 12 12 4 22 5,5A,5B,5C 5,5A,5B,5C 11 11 11 66 12 12 77 3 99 88 10 10 (1) Axle Housing. (2) Carrier (3) Brake Housing Left/Right. (4) Pinion. (5) Crown wheel/differential. (6) Drive Shaft Left/right. (7) Ring Gear/Hub. left/right. (8) Pneumatic Tire Wheel Flange Left/right. (10) Spindle. (11) Axle Mounting Pads. (12) Mast Mounting Hooks. The Axle Consists of 4 main sections (9) Multi-disc brake left/right.
Axle power flow Power is transmitted by the transmission output shaft to the pinion (4) which meshes with and drives the crownwheel (5), which is mounted to the differential. 4 5 The differential is part of the drive axle. It is a single reduction unit with a differential drive gear fastened on the differential case. When the lift truck moves in a forward direction and there is the same traction under each wheel, torgue in each axle and pinion gears (5B) are balanced.
Axle Lubrication Schematic PUMP PUMP 3 3 11 22 33 The axle is lubricated by means of the transmissionmounted lubricant pump (2) which gets oil from the axle suction port (1) and supplies it to the hub section pressure parts (3) to lubricate and cool hub drive and multi-disc brakes. Oil returns to the sump through the drive shaft bearings and axle housing.
Hydraulic System (1) Transmission Oil Sump. (2) Oil Pump. (3) Primary Filter. (4) Main Valve. (5) Orifice. (6) Inching Valve. (7) Modulating Valve. (7A) Load Piston. (7B) Modulating Valve Orifice. (8) Selector Valve. (9) Solenoid Valve Forward. (10) Solenoid Valve Reverse. (11) Forward Clutch. (12) Reverse Clutch. (13) Relief Valve. (14) Torque Converter. (15) Relief Valve. (16) Converter Bypass. (17) Oil Cooler. (18) Torque Converter Supply Bypass.
Transmission Hydraulic System The transmission hydraulic system is explained in three sections. The first section is the oil pump, filter, torque converter and oil cooler systems. The second section is the transmission lubrication system. The third section is the transmission hydraulic control system which controls the lift truck direction control. 4 Pump, Filter, Torque Converter And Oil Cooler Systems 6 The oil for the operation and lubrication of the transmission is made available by pump (2).
Power Train 26 Systems Operation
When the transmission is in NEUTRAL position with the engine running, oil is pulled from reservoir and the strainer assembly (1) to pump (2). From there, pump oil flows through the primary filter (3) to main relief valve (4). Oil will also flow through orifice (18) to lubricate the torque converter during hot, low speed conditions. Neutral Position Transmission Hydraulic System-Neutral (1) Transmission Oil Sump. (2) Oil Pump. (3) Primary Filter.
Power Train 28 Systems Operation
When the transmission is in FORWARD, the oil flow from the reservoir, through the pump, primary filter, torque converter and oil cooler circuits will be the same as explained in NEUTRAL position. Forward Direction Transmission Hydraulic System-Forward (1) Transmission Oil Sump. Oil will flow from the main relief valve to inching valve (6). Without inching (inching pedal up and valve in), oil flows around and through the center of reducing spool (6A) to the bottom of the spool.
Power Train 30 Systems Operation
When the transmission is in REVERSE, the oil flow from the reservoir, through the pump, primary filter, torque converter and oil cooler circuits will be the same as explained in NEUTRAL position. Reverse Direction Transmission Hydraulic System-Reverse (1) Transmission Oil Sump. Oil will flow from the main relief valve to inching valve (6). Without inching (inching pedal up and valve in), oil flows around and through the center of reducing spool (6A) to the bottom of the spool.
Power Train 32 Systems Operation
When the transmission is in FORWARD (or REVERSE) during INCHING, the oil flow from the reservoir, through the pump, filter, torque converter and oil cooler circuits will be the same as explained in NEUTRAL position. Forward Direction During Inching Transmission Hydraulic System-Forward Inching (1) Transmission Oil Sump. Oil will flow from the main relief valve through a passage, to inching valve (6).
Basic Control Schematic DR DR DR FWD CLUTCH REV CLUTCH SOLENOID SOLENOID DR DR DR PUMP The control schematic is shown below. The system consists of 2 valve bores: 1. Modulating valve 2.
Modulating valve function SPRING MODULATING VALVE LOAD PISTON ORIFICE DR REACTION SLUG DR DR FLOW TO SELECTOR SPOOLS PUMP Figure 1 The modulating valve consists of 5 basic elements: 1. Orifice 2. Springs 3. Load piston 4. Modulating valve 5. Reaction slug The function of the modulating valve is to control clutch pressure during a shift.
Modulating valve movement during clutch fill Modulation of clutch to top pressure Figure 3 Figure 2 MODULA TION When a new direction is selected by the operator, the selector spools open up a circuit to the new clutch piston. System pressure drops as the new clutch piston is stroking. This drop in supply pressure causes a force imbalance on the modulating valve / reaction slug pressure becomes smaller.
Selector spools Figure 5 The selector spool circuits are arranged in such a way that once a gear (forward or reverse) is selected the opposite solenoid supply is shut off and drained. This is done to prevent any electrical or malfunction of the other solenoid from giving a sudden and unexpected shift. In addition the two selector spools are arranged so they cannot select both forward and reverse at the same time because they mechanically interfere with each other. The selector spools have two areas: 1.
Troubleshooting 3. Actuate the controls for the forward direction and then for the reverse direction. The actuation must give the same positive action to the hydraulic control circuit for clutch engagement in both directions. Troubleshooting can be difficult. A list of possible problems and corrections is on the pages that follow. 4. Remove and check the filter element for loose particles. Check the strainer behind the transmission oil plug for foreign material.
Check List During Operation g. Leakage inside the transmission. Worn or broken metal seal rings on input or reverse shaft. Worn or broken seals around clutch piston. Modulating valve assemblies stuck Because of contaminated oil Problem: Engine starts with directional control switch in FORWARD or REVERSE. Probable cause: 1. Directional control switch is defective 3. External oil lines are not connected correctly. Problem: Transmission shifts with parking brake engaged. 4.
7. Low oil flow through converter. Converter relief valve stuck open (converter bypass orifice plugged) Check List From Operation Noises Problem: Noise in NEUTRAL only. 8. Incorrect use of vehicle. Loads are too heavy for the lift truck. Probable cause: 9. Too much inching operation (slipping the clutch plates and discs). 1. Worn one-way clutch in torque converter. 2. Low oil level (pump cavitation). 10. Too much stalling of torque converter. 3. Worn bearing next to pump. 11.
6. Too much or too little gear backlash. 2. Loss at bevel input pinion shaft. 7. Loose or worn pinion bearings. a. Lubricant above specification level. 8. Loose or worn shaft bearings. b. Wrong kind of lubricant. 9. Loose or worn differential bearings. c. Restriction of axle housing breather. Problem: Noise at different intervals. d. Pinion oil seal worn or not installed correctly. Probable cause: Problem: Drive wheels do not turn. 1. Bolts on drive gear not tightened correctly.
Problem: Pressure to one clutch is low. Problem: High converter charge pressure. Probable cause: Probable cause: 1. Clutch piston seal alignment is not correct, oil leaks through. 1. A plugged converter bypass orifice. 2. A restriction inside the converter assembly. 2. Seal rings on shaft or clutch piston seals are broken or worn. 3. A plugged oil flow passage. 3. Modulating valve assembly stuck. Problem: Low converter charge pressure. Problem: Low pump pressure.
Problem: High stall speed in one direction. Problem: Modulation spool problems. Probable cause: 1. Slow or no modulation of both clutches 1. There is a leak in the clutch circuit. (If only 1 clutch does not modulate correctly then the problem is either with the selector spool or it is a problem in the transmission). 2. There is a failure in that clutch assembly (clutch Probable cause: slipping). 1. orifice plugged with debris Problem: Selector spool problems. 2. Modulation valve stuck 1.
Transmission and Drive Axle Tests And Adjustments Most problems in the hydraulic circuit can normally be found when the pump pressure is checked. If more information is necessary, gauges can be installed at each pressure tap location. Locations of the pressure taps and procedures for testing are given as follows. If any of the pressures are not correct, refer to Troubleshooting For Problems and Probable Causes. Transmission Pressure Tests Tools Needed Pressure Gauge Group 1.
Pressure Tap Locations – Transmission Control Group Main Pressure Tap 6 Reverse Pressure Tap 5 Forward Pressure Tap 4 Converter Charge Pressure Tap 3 Converter Outlet Pressure Tap 2 Temperature Sensor To Cooler From Cooler Lubrication Pressure Tap 7 Power Train 45 Testing and Adjusting
Converter Stall Test 7. Check lubrication pressure at pressure tap (7) with the transmission in neutral. NOTE: Make sure that the transmission oil is at the correct temperature for operation before tests are made. a. If lubrication pressure is low, see Problem: Low lubrication pressure in Troubleshooting. The converter stall test is a test to check engine power. It can also be used to locate a problem in the transmission or torque converter when the condition of the engine is known.
The stall speed must be the same in FORWARD and REVERSE. If the stall speed is high in FORWARD and REVERSE, check the following: NOTICE To make sure that the transmission oil does not get hot, do not hold the transmission in a stall condition for more than ten seconds. After the transmission is stalled, put the controls in NEUTRAL and run the engine at 1200 to 1500 RPM to cool the oil. a. Check for air in the oil. b.
Maintenance Transmission and Drive Axle Transmission Change Filter Grease Parking Brake Lever Oil Filler And Dipstick Pin And Nut Of Parking Brake Oil Drain Plug And Suction Strainer ATTENTION : When changing oil, replace filter and clean suction strainer.
Drive Axle Combined Oil Filler and Dipstick Brake Cooling Port Pump Suction Port Brake Cooling Port Oil Drain Plug Port ATTENTION : Clean suction strainer when replacing oil.
Electric Control System Tests Power To Directional Control Switch Check 1. Put the directional control lever in neutral. Remove the cover from the front side of the steering support assembly. Tools Needed Digital Multimeter 1 2. Disconnect harness connector (2) from directional control switch connector(1). NOTE : Refer to Schematic. Checks on the transmission directional control electrical circuit can be done with a Digital Multimeter.
Directional Control Switch Check 5. Turn the ignition switch OFF and put the multimeter on the 200 ohm range. 6. Check continuity between pins 4 and 7 of connector (1) with the switch in neutral. forward and then reverse positions. There should be continuity in neutral and no continuity in forward and reverse. a. If the above checks are correct, do Step 7. b. If any of the above checks are not correct, replace the directional control switch.
2 3 1 4 Transmission Directional Control Schematic (1) Directional Switch Connector.
Inching Pedal Adjustment Transmission Control Harness Check To check the inching valve adjustment and operation, do the procedure that follows : 3 WARNING When this procedure is used, the lift truck must be in an area clear of obstructions. There must be one operator with all other personnel away from the lift truck. Check the operation of the brakes before the test is made. 5 Transmission Control Harness. (3) Harness. (5) Connector 1. With the engine at idle speed, put the transmission in FORWARD.
WARNING To prevent personal injury, when the inching pedal is adjusted, move the truck to a clear area that is level. Keep all other personnel away from the lift truck. Use lifting equipment or a safe method to lift the front of the lift truck until the drive wheels are off the floor. Put wood blocks or jack stands of the correct capacity under it to hold it in this position while the inching pedal is adjusted. 2. Raise the front of the lift truck off the floor.
Adjustments on Drive axle and Transmission 4. Calaulate the shimpack thickness according to the following formula. Shimpack thickness = A-(127+B+C) Example) if A=160.50, B=32.00, C=+0.05 Then, shimpack thickness =160.50-(127+32.00+0.55) = 1.45mm Axle, Pinion, crown gear * To minimize the measuring error, measure three places at least and average them. 1. Measure the depth from center of diff. carrier to the seat of pinion bearing cup. (Dimension A) 5.
8. Install bearing nuts for correct bridge position and lightly torque them to achieve bearing preload. 11. When drag is correct, mark position of nuts both on nuts and bridge. 9. Tap on differential on both sides to achieve correct bearing cone position, rotate differential (3-5 times). 12. After marking of position remove differential assy. 10. Check drag 19.6 N.m (14.5 lb.ft) on rotating differential.
Installation of Pinion 4. Tap bearing cone to correct position(Rotate pinion 3-5 times) 1. Install cup of rear pinion bearing 5. Assemble yoke and nut and tighten flange nut to 180 ±15 N∙m (133±11 lb∙ft) 2. Install spacer and shims on pinion (basic thickness 1.5mm (0.059 in)). 6. Measure the rolling torque. The value of rolling torque should be 1.5~2.0 N∙m (1.1~1.5 lb∙ft) 3. Install bearing cone. 7. If the rolling torque exceeds 2 N∙m, add one shim and if it is lower than 1.5 N∙m, subtract one shim 8.
Adjustment of Crown Wheel 3. Tap on both sides of the differential to achieve correct position of bearing cups. 1. Torque crown wheel bolts to 80 N·m (59 lb·ft). 4. Check backlash between pinion and crown gear in 3 different positions. Backlash shall be 0.15-0.25mm (0.006-0.010 in) 2. Install differential assy., to previously mounted position (rotate both nuts simultaneously to maintain bearing preload). 5. Check contact face by rotating pinion in both directions, hold back crown wheel.
6. Check contact area position and correct in accordance with specification if neccessary. 9. Position not correct. 7. Position not correct 10. After correct adjustment of contact area secure differential nut with cotter pin. 8. Correct position.
Adjustment of Wheel Bearings 4. Remove wheel nut for lockwasher installation. 1. Assemble outer hub bearing without lockwasher. 5. Install lockwasher and nut. 2. Tighten wheel nut to 135 ± 14 N·m (100±10 lb·ft). 6. Tighten nut to 50 ±5 N·m (37±3 lb·ft). 3.
