1 01 06-18 SUBJECT DATE Belt Drive January 2018 Additions, Revisions, or Updates Publication Number / Title Platform Section Title Change DDC-SVC-MAN-0190 DDC-SVC-MAN-0081 GHG17 DD Heavy Duty DD Heavy Duty Description and Operation of the Belt Drive Tensioner System Removal of the Belt Tensioner Inspection of the Belt Tensioner Installation of the Belt Tensioner Description and Operation of the Belt Drive Tensioner System Removal of the Belt Tensioner Inspection of the Belt Tensioner Installation of the Belt Tensioner Updates to the Description and Operation, Removal, and Installation procedures. New Inspection procedures were added. All information subject to change without notice. 3
2 Description and Operation of the Belt Drive Tensioner System 2 Description and Operation of the Belt Drive Tensioner System The engine uses two poly-v-belts. Since this type of belt is very flexible, a number of major assemblies can be driven by one poly-v-belt. The alternator, refrigerant compressor, and coolant pump are driven by one, eight-ribbed, poly-v-belt. The fan clutch and the engine fan are driven by one, ten-ribbed, poly-v-belt. The purpose of the belt drive tensioner is to provide constant and adequate tension to the belt drive, to prevent the belts from slipping. The belt tensioners are firmly bolted onto the accessory bracket. The tensioning arms with tensioner pulleys are turned counterclockwise by the force of the springs to provide the required tension in the belts. There is a square hole in each tensioning arm to install a ½ inch socket tool for removal and installation of the poly-v-belts. The outer poly-v-belt must be removed before removing the inner poly-v-belt. 1. 2. 3. 4. 5. Vibration Damper Poly-V-Belt for the Fan Drive Alternator Pulley Fan Drive Idler Pulley Poly-V-Belt for Alternator, Refrigerant Compressor and Coolant Pump 6. Belt Tensioner Pulley 7. Refrigerant Compressor Pulley 8. 9. 10. 11. 12. 13. 14. Refrigerant Compressor Belt Tensioner Fan Clutch Assembly Accessory Drive Idler Pulley and Spacer Coolant Pump Accessory Drive Idler Pulley Bracket Accessory Drive Idler Pulley Figure 1. Belt Drive System 4 All information subject to change without notice. Copyright 2018 DETROIT DIESEL CORPORATION 01 06-18
1. Fan Drive ( Grooved) Idler Arm Square Hole 2. Accessory Drive ( Non-Grooved) Idler Arm Square Hole Figure 2. Belt Drive Tensioner 3. Accessory Drive ( Non-Grooved) Idler Arm Tension- Locking Pin Hole 4. Fan Drive ( Grooved) Idler Arm Tension-Locking Pin Hole All information subject to change without notice. 5
3 Removal of the Belt Tensioner 3 Removal of the Belt Tensioner Remove as follows: 1. Shut off the engine, apply the parking brake, chock the wheels, and perform any other applicable safety steps. 2. Open the hood. CAUTION: ELECTRICAL SHOCK To avoid injury from electrical shock, use care when connecting battery cables. The magnetic switch studs are at battery voltage. 3. Disconnect the batteries. Refer to OEM procedures. 4. If necessary, remove the bumper. Refer to the Original Equipment Manufacturer (OEM) procedures. 5. Remove the two poly-v-belts. Refer to section "Removal of the Poly-V-Belts". 6. Remove the three bolts from the tensioner (2). 7. Remove the belt tensioner (1) from the accessory mounting bracket. 6 All information subject to change without notice. Copyright 2018 DETROIT DIESEL CORPORATION 01 06-18
4 Inspection of the Belt Tensioner NOTE: There are no serviceable components for the belt tensioner. If any damage is found, the belt tensioner must be replaced as a complete assembly. 1. Inspect the belt tensioner assembly for any cracks or signs of damage. Replace the tensioner assembly if damage is found. 2. Make sure the belt tensioner is applying constant adequate tension. Debris entering the pivot points can affect the operation of the tensioner. When the tensioner is flexed back and forth there should be no sticking or binding points in the movement of the tensioning arms. 3. Inspect the belt tensioner for oil leaks. There should be no oil leaking from the belt tensioner. If oil is present, ensure the oil is originating from the belt tensioner assembly before replacing the tensioner. 4. Check the belt tensioner pulleys for proper rotation and alignment. They should move freely. All information subject to change without notice. 7
5 Installation of the Belt Tensioner 5 Installation of the Belt Tensioner Install as follows: 1. Install the belt tensioner (1) to the accessory mounting bracket. 2. Install the three belt tensioner mounting bolts (2). Torque to 60 N m (44 lb ft). 3. Install the two poly-v-belts. Refer to section "Installation of the Poly-V-Belts". CAUTION: ELECTRICAL SHOCK To avoid injury from electrical shock, use care when connecting battery cables. The magnetic switch studs are at battery voltage. 4. Reconnect the batteries. WARNING: PERSONAL INJURY Diesel engine exhaust and some of its constituents are known to the State of California to cause cancer, birth defects, and other reproductive harm. Always start and operate an engine in a well ventilated area. If operating an engine in an enclosed area, vent the exhaust to the outside. Do not modify or tamper with the exhaust system or emission control system. WARNING: PERSONAL INJURY To avoid injury before starting and running the engine, ensure the vehicle is parked on a level surface, parking brake is set, and the wheels are blocked. 8 All information subject to change without notice. Copyright 2018 DETROIT DIESEL CORPORATION 01 06-18
WARNING: ENGINE EXHAUST To avoid injury from inhaling engine exhaust, always operate the engine in a well-ventilated area. Engine exhaust is toxic. 5. Start the engine and inspect for proper belt alignment and belt drive operation. 6. If removed, install the bumper. Refer to the Original Equipment Manufacturer (OEM) procedures. 7. Close the hood. All information subject to change without notice. 9
6 Description and Operation of the Belt Drive Tensioner System 6 Description and Operation of the Belt Drive Tensioner System The engine uses two poly-v-belts. Since this type of belt is very flexible, a number of major assemblies can be driven by one poly-v-belt. The alternator, refrigerant compressor, and coolant pump are driven by one eight-ribbed poly-v-belt. The fan clutch and the engine fan are driven by one ten-ribbed poly-v-belt. The purpose of the belt drive tensioner is to provide constant and adequate tension to the belt drive, to prevent the belts from slipping. The belt tensioners are firmly bolted onto the accessory bracket. The tensioning arms with tensioner pulleys are turned counterclockwise by the force of the springs to provide the required tension in the belts. There is a square hole in each tensioning arm to install a ½ in socket tool for removal and installation of the poly-v-belts. The outer poly-v-belt must be removed before removing the inner poly-v-belt. 1. 2. 3. 4. 5. Vibration Damper Fan Drive Poly-V-Belt Alternator Fan Drive Idler Pulley Poly-V-Belt for Alternator, Refrigerant Compressor and Coolant Pump 6. Belt Tensioner Pulley 7. Refrigerant Compressor 10 8. 9. 10. 11. 12. 13. 14. Accessory Mounting Bracket Belt Tensioner Fan Clutch Assembly Accessory Drive Idler Pulley and Spacer Coolant Pump Accessory Drive Idler Pulley Bracket Accessory Drive Idler Pulley All information subject to change without notice. Copyright 2018 DETROIT DIESEL CORPORATION 01 06-18
Figure 3. Belt Drive Tensioner and Related Parts 1. Fan Drive ( Grooved) Idler Arm Square Hole 2. Accessory Drive ( Non-Grooved) Idler Arm Square Hole Figure 4. Belt Drive Tensioner 3. Accessory Drive ( Non-Grooved) Idler Arm Tension- Locking Pin Hole 4. Fan Drive ( Grooved) Idler Arm Tension-Locking Pin Hole All information subject to change without notice. 11
7 Removal of the Belt Tensioner 7 Removal of the Belt Tensioner Remove as follows: 1. Shut off the engine, apply the parking brake, chock the wheels, and perform any other applicable safety steps. 2. Open the hood. CAUTION: ELECTRICAL SHOCK To avoid injury from electrical shock, use care when connecting battery cables. The magnetic switch studs are at battery voltage. 3. Disconnect the batteries. 4. If necessary, remove the bumper. Refer to the Original Equipment Manufacturer (OEM) procedures. 5. Remove the two poly-v-belts. Refer to section "Removal of the Poly-V-Belts" 6. Remove the three bolts from the tensioner. 7. Remove the tensioner from the accessory mounting bracket. 12 All information subject to change without notice. Copyright 2018 DETROIT DIESEL CORPORATION 01 06-18
8 Inspection of the Belt Tensioner NOTE: There are no serviceable components for the belt tensioner. If any damage is found, the belt tensioner must be replaced as a complete assembly. 1. Inspect the belt tensioner assembly for any cracks or signs of damage. Replace the tensioner assembly if damage is found. 2. Make sure the belt tensioner is applying constant adequate tension. When the tensioner is flexed back and forth there should be no sticking or binding points in the movement of the tensioning arms. 3. Inspect the belt tensioner for oil leaks. There should be no oil leaking from the belt tensioner. If oil is present, ensure the oil is originating from the belt tensioner assembly before replacing the tensioner. 4. Check the belt tensioner pulleys for proper rotation and alignment. They should move freely. All information subject to change without notice. 13
9 Installation of the Belt Tensioner 9 Installation of the Belt Tensioner Install as follows: 1. Install the belt tensioner onto the accessory mounting bracket. 2. Install the three belt tensioner mounting bolts. Torque to 60 N m (44 lb ft). 3. Install the two poly-v-belts. Refer to section "Installation of the Poly-V-Belts" CAUTION: ELECTRICAL SHOCK To avoid injury from electrical shock, use care when connecting battery cables. The magnetic switch studs are at battery voltage. 4. Reconnect the battery power to the engine. Refer to OEM procedures. WARNING: PERSONAL INJURY Diesel engine exhaust and some of its constituents are known to the State of California to cause cancer, birth defects, and other reproductive harm. Always start and operate an engine in a well ventilated area. If operating an engine in an enclosed area, vent the exhaust to the outside. Do not modify or tamper with the exhaust system or emission control system. WARNING: PERSONAL INJURY To avoid injury before starting and running the engine, ensure the vehicle is parked on a level surface, parking brake is set, and the wheels are blocked. 14 All information subject to change without notice. Copyright 2018 DETROIT DIESEL CORPORATION 01 06-18
WARNING: ENGINE EXHAUST To avoid injury from inhaling engine exhaust, always operate the engine in a well-ventilated area. Engine exhaust is toxic. 5. Start the engine and inspect for proper belt alignment and belt drive operation. 6. If removed, install the bumper. Refer to the Original Equipment Manufacturer (OEM) procedures. 7. Close the hood. All information subject to change without notice. 15