 |
|
Personal injury or death can result from sudden machine movement. Sudden movement of the machine can cause injury to persons on or near the machine. To prevent injury or death, make sure that the area around the machine is clear of personnel and obstructions before operating the machine. |
|
|
Personal injury can result from hydraulic oil pressure and hot oil. Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system. Make sure all of the attachments have been lowered, oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand. |
|
|
Escaping fluid under pressure, even a pinhole size leak, can penetrate body tissue, causing serious injury, and possible death. If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury. Always use a board or cardboard when checking for a leak. |
| NOTICE |
|---|
|
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to Special Publication, NENG2500, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat products. Dispose of all fluids according to local regulations and mandates. |
Note: Operate the machine in each direction and in all speeds. Note the noises that are not normal and find the sources of the noises. If the machine is not operating correctly, refer to the following "Clutch Engagement is Sudden, Causing Jerky Shifting" .
- Transmission does not operate in any speed or slips in all speeds.
- Transmission overheats.
- Pump noise that is not heard normally.
- Noise in the transmission that is not normal
- Transmission does not operate in REVERSE.
- Transmission does not operate in FIRST SPEED FORWARD, SECOND SPEED FORWARD, or FOURTH SPEED FORWARD (Forward Low Speeds).
- Transmission does not operate in THIRD FORWARD SPEED or FIFTH FORWARD SPEED (Forward High Speeds).
- Transmission does not operate in SECOND SPEED FORWARD, THIRD SPEED FORWARD, or SECOND SPEED REVERSE.
- Transmission does not operate in FOURTH SPEED FORWARD, FIFTH SPEED FORWARD, or THIRD SPEED REVERSE.
- Transmission does not operate in FIRST SPEED FORWARD or FIRST SPEED REVERSE.
- Clutch engagement is sudden, causing jerky shifting
- Clutch engagement is slow, causing slow shifting in all gears
- Clutch engagement is slow in all FORWARD gears, in all REVERSE gears, or in any one gear speed (FORWARD and REVERSE).
- Machine does not move and engine speed lugs when the transmission is engaged.
- Engine is running with parking brake engaged, however, the action alarm does not sound when the transmission is put into the FORWARD or REVERSE direction.
- Backup alarm does not sound when the transmission is put in REVERSE.
- Stall speed is low.
- Stall speed is high when the machine is operated in both directions.
- Stall speed is high when the machine is operated in one direction or in one speed.
Note: In the following section, refer to Hydraulic Schematic , UENR3116 and Electrical Schematic , UENR3117 when troubleshooting the machine.
Check for any service codes that may have been generated before troubleshooting a problem. Use the built-in electrical diagnostics that are performed with the electronic control module to determine the service codes for the electronic control module.
Note: This machine is equipped with a Machine electronic control. The Machine electronic control has built-in system diagnostics used to detect faults in the electronic system. For additional information on the operation and troubleshooting of the electronic control module (ECM), refer to information in this manual. For transmission testing and operation information, refer to Systems Operation, Testing and Adjusting, UENR3110, "950M and 962M Wheel Loaders Power Train, Steering, Braking, Hydraulic, and Machine Systems".
Note: The following transmission problems list possible causes that should be considered when the specific conditions have been identified.
Transmission Does Not Operate in any Speed or Slips in all Speeds
Probable causes include:
- The fuse for the power train control is missing or broken.
- There is a problem in the electrical circuit.
- Oil pump is not primed.
- Oil pump failure.
- There is an electrical or mechanical problem with the main relief valve.
- There is a hydraulic fluid leak.
- The torque converter is not primed.
- Torque converter failure.
- Mechanical linkage between the torque converter and the transmission failure.
- Multiple transmission clutch failure.
- Parking brake failure.
- Service brake or lower power train failure.
Probable causes include:
- The oil level is low.
- There is a dirty oil strainer or a restriction in the oil flow circuit.
- Oil pump failure.
- Air leaks on the inlet side of the pump.
- There is leakage inside the transmission (worn seals around the clutch piston).
- The modulating relief valve is stuck open.
- There is a torque converter failure.
- There is a mechanical failure in the transmission.
- Clutch discs and clutch plates are excessively worn.
Probable causes include:
- Coolant level in the radiator is low.
- The machine is being used for the wrong application. There is too much torque converter slip, which is caused by too much load.
- Incorrect transmission gear is being used for the load that is on the machine. Shift to a lower gear.
- The temperature gauge is faulty.
- The oil level is incorrectly high or low.
- The oil cooler or oil lines are restricted.
Probable causes include:
- Low oil pressure. Refer to the Problem: The Transmission Does Not Operate In Any Speed Or The Transmission Slips In All Speeds.
- A clutch is damaged.
- Oil flow is low. Low flow may be caused by pump wear or by leakage in the transmission hydraulic system.
- There is air in the oil. Air in the oil may be caused by air leaks on the intake side of the pump.
- The magnetic screen for the pump inlet is plugged.
- The torque converter inlet ratio valve is stuck open. A stuck valve causes low oil flow through the torque converter.
Clutch or Clutches are Not Fully Released ("Clutch Drag")
Probable causes include:
- There are warped plates or warped discs.
- A return spring is broken or weak.
Pump Noise that is Not Normally Heard
Probable causes include:
- A loud noise at short intervals indicates that foreign material is in the transmission hydraulic system.
- A constant loud noise indicates pump failure.
- There is air at the inlet side of the pump.
Noise in the Transmission that is Not Normal
Probable causes include:
- Transmission components are worn or damaged.
- Gears are damaged.
- The teeth of the clutch plates and/or clutch discs are worn.
- The clutch plates are slipping or noise from the clutch discs.
Transmission does Not Operate in REVERSE
Probable causes include:
- Number 3 REVERSE clutch solenoid is inoperative.
- There is a problem in the electrical circuit.
REVERSE Clutch is Not Engaged or Slips
Probable causes include:
- Low oil pressure due to leaking piston seals.
- The clutch discs and clutch plates have too much wear.
- Clutch components are broken.
Probable causes include:
- Number 1 FORWARD LOW clutch solenoid is inoperative.
- There is a problem in the electrical circuit.
FORWARD LOW Clutch Is Not Engaged or Slips
Probable causes include:
- Low oil pressure due to leaking piston seals.
- The clutch discs and clutch plates have too much wear.
- Clutch components are broken.
Transmission Does Not Operate in Forward High Speeds (THIRD FORWARD SPEED or FIFTH FORWARD SPEED)
Probable causes include:
- Number 2 FORWARD HIGH clutch solenoid is inoperative.
- There is a problem in the electrical circuit.
FORWARD HIGH Clutch is Not Engaged or Slips
Probable causes include:
- Low oil pressure due to leaking piston seals.
- The clutch discs and clutch plates have too much wear.
- Clutch components are broken.
Transmission Does Not Operate in SECOND SPEED FORWARD, THIRD SPEED FORWARD, or SECOND SPEED REVERSE
Probable causes include:
- Number 4 speed clutch solenoid is inoperative
- There is a problem in the electrical circuit.
Number 4 Speed Clutch is Not Engaged or Slips
Probable causes include:
- Low oil pressure due to leaking piston seals.
- The clutch discs and clutch plates have too much wear.
- Clutch components are broken.
Transmission does Not Operate in FOURTH SPEED FORWARD, FIFTH SPEED FORWARD, or THIRD SPEED REVERSE
Probable causes include:
- Number 5 speed clutch solenoid THIRD SPEED is inoperative.
- There is a problem in the electrical circuit.
Number 5 Speed Clutch is Not Engaged or Slips
Probable causes include:
- Low oil pressure due to leaking piston seals.
- The clutch discs and clutch plates have too much wear.
- Clutch components are broken.
Transmission Does Not Operate in FIRST SPEED FORWARD, or FIRST SPEED REVERSE
Probable causes include:
- Number 6 speed clutch solenoid SPEED is inoperative.
- There is a problem in the electrical circuit.
The FIRST SPEED Clutch is Not Engaged or Slips
Probable causes include:
- Low oil pressure due to leaking piston seals.
- The clutch discs and clutch plates have too much wear.
- Clutch components are broken.
Clutch Engagement is Sudden, Causing Jerky Shifting
Probable causes include:
- Calibration needed on clutch modulating valves.
- A clutch piston is sticking.
- A speed sensor has malfunctioned.
Clutch Engagement is Slow, Causing Slow Shifting in all Gears
Note: Slow clutch engagement causes slow shifting in all gears.
Probable causes include:
- Oil pressure is low. Refer to the Problem: The transmission does not operate in any speed or the transmission slips in all speeds.
- Modulating relief valve is stuck.
Probable causes include:
- Clutch pressure is low because of leaking seals on the piston for the affected gear.
Machine does Not Move and Engine Lugs when Transmission is Engaged
Probable causes include:
- Service brakes are locked up.
- The parking brake is not released. Also, the parking brake may be locked up.
- There is a mechanical failure in a differential (front differential or rear differential).
- There is a mechanical failure in a final drive.
- Gears in the transmission do not turn because there is a mechanical failure in the transmission or too many clutches are engaged.
Probable causes include:
- There is a problem in the electrical circuit.
Backup Alarm does Not Sound when the Transmission is put into REVERSE
Probable causes include:
- The backup alarm fuse has failed.
- The backup alarm has failed.
- There is a problem in the electrical circuit.
Probable causes include:
- Engine performance is not correct.
- The oil is cold.
Stall Speed is High when the Machine is Operated in Both Directions
Probable causes include:
- Oil level is low.
- There is air in the oil.
- Direction clutches are slipping.
- There is a failure in the torque converter.
- The torque converter impeller clutch is slipping.
Stall Speed is High when the Machine is Operated in One Direction or in One Speed
Probable causes include:
- There is a leak in the clutch circuit.
- There is a failure in the direction clutch or in the speed clutch that has high stall speed.