PULLEY - GENERATOR DECOUPLER
DESCRIPTION
The generator decoupler is used only with certain engines. The decoupler is used in place of the standard generator drive pulley .
OPERATION
The generator decoupler is used only with certain engines. The decoupler is a one-way clutch designed to help reduce belt tension fluctuation, vibration, reduce fatigue loads, improve belt life, reduce hubloads on components, and reduce noise. Dry operation is used (no grease or lubricants). The decoupler is not temperature sensitive and also has a low sensitivity to electrical load. The decoupler is a non-serviceable item and is to be replaced as an assembly.
DIAGNOSIS AND TESTING - GENERATOR DECOUPLER
| CONDITION |
POSSIBLE CAUSES |
CORRECTION |
| Does not drive generator (generator not charging) |
Internal failure |
Replace decoupler |
| Noise coming from decoupler |
Internal failure |
Replace decoupler |
REMOVAL
The generator decoupler (2) is used only with certain engines.
Two different type generator decoupler pulleys are used. One can be identified by the use of machined splines (3).
The other can be identified by a hex opening (2) and will not use splines.
Different special tools are required to service each different decoupler. Refer to following procedure.
INA Decoupler
1. Disconnect negative battery cable.
2. Remove generator and accessory drive belt. Refer to Generator Removal.
3. Position Special Tool #8823 (VM.1048) (2) into decoupler (1).
4. Determine if end of generator shaft is hex shaped (2) or.....
5. .....or is splined (2).
6. If hex is used, insert a 10mm deep socket (1) into tool #8823 (VM.1048) (2).
7. If splined, insert a 5/16” 6-point hex driver, or a 10mm 12-point triple square driver (1) into tool #8823 (VM.1048) (2).
8. The generator shaft uses conventional right-hand threads to attach decoupler. To break decoupler loose from generator threads, rotate tools as shown
9. After breaking loose with tools, unthread decoupler by hand from generator.
Litens Decoupler
1. Disconnect negative battery cable.
2. Remove generator and accessory drive belt. Refer to Generator Removal.
3. Position Special Tool #8433 into decoupler. Align to hex end of generator shaft.
4. The generator shaft uses conventional right-hand threads to attach decoupler. To break decoupler loose from generator threads, rotate end of tool clockwise.
5. After breaking loose with tool, unthread decoupler by hand from generator.
INSTALLATION
INA Decoupler
1. Thread decoupler pulley onto generator shaft by hand (right-hand threads).
2. Position Special Tool #8823 (VM.1048) (2) into decoupler.
3. Determine if end of generator shaft is hex shaped or is splined. If hex is used, insert a 10mmM deep socket (1) into tool #8823 (VM.1048) (2).
4. If splined, insert a 5/16” 6-point hex driver, or a 10mm 12-point triple square driver (1) into tool #8823 (VM.1048) (2).
5. Do not use an adjustable, ratcheting “click type” torque wrench. Most “click type” wrenches will only allow torque to be applied in a clockwise rotation. Use a dial-type or beam-type wrench. Tighten in directions as shown. Refer to torque specifications.
6. Install accessory drive belt, and generator. Refer to Generator Installation.
7. Connect negative battery cable.
Litens Decoupler
1. Thread decoupler pulley onto generator shaft by hand (right-hand threads).
2. Position Special Tool 8433 into decoupler. Align tool to hex end of generator shaft.
3. Do not use an adjustable, ratcheting “click type” torque wrench. Most “click type” wrenches will only allow torque to be applied in a clockwise rotation. Use a dial-type or beam-type wrench. Tighten in direction as shown. Refer to torque specifications.
4. Install accessory drive belt, and generator. Refer to Generator Installation.
5. Connect negative battery cable.