Torque Specs for Cummins ISC, QSC, ISL, and QSL Engines: Your Complete Guide

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The Cummins ISC, QSC, ISL, and QSL engines are known for their versatility and durability, powering a wide range of vehicles and equipment, from commercial trucks to marine vessels. Maintaining these engines at peak performance requires precise torque specifications for various components. In this guide, we provide the critical torque specs you need to ensure reliability, performance, and longevity in your Cummins ISC, QSC, ISL, and QSL engines.

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CYLINDER HEAD

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PART/MATERIAL/COLOR

LENGTH

TORQUE VALUE IN NM [ FT-LB ]

CYLINDER HEAD CAPSCREWS (CAPS FUEL SYSTEM)	N/A	1. 50 N•M [ 37 FT-LB ] 2. 148 N•M [ 109 FT-LB ] 3. 148 N•M [ 109 FT-LB ] 4. ADVANCE 90 DEGREES.
CYLINDER HEAD CAPSCREWS (COMMON RAIL FUEL SYSTEM)	N/A	1. 50 N•M [ 37 FT-LB ] 2. 150 N•M [ 111 FT-LB ] 3. LOOSEN ALL CAPSCREWS 4. 115 N•M [ 85 FT-LB ] 5. 115 N•M [ 85 FT-LB ] 6. ADVANCE 120 DEGREES.
CYLINDER HEAD CAPSCREWS (CYLINDER BLOCK SERIAL NUMBERS: 9826882 & HIGHER)	N/A	1. 50 N•M [ 37 FT-LB ] 2. 150 N•M [ 111 FT-LB ] 3. LOOSEN ALL CAPSCREWS 4. 115 N•M [ 85 FT-LB ] 5. 115 N•M [ 85 FT-LB ] 6. ADVANCE 150 DEGREES.

 

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PISTON AND CONNECTING ROD ASSEMBLY

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PART/MATERIAL/COLOR

LENGTH

TORQUE VALUE IN NM [ FT-LB ]

ENGINES WITH CONNECTING ROD STUDS AND NUTS	N/A	1. 60 N•M [ 44 FT-LB ] 2. LOOSEN CAPSCREWS 3. 70 N•M [ 52 FT-LB ] 4. ADVANCE 90 DEGREES
ENGINES WITH CONNECTING ROD CAPSCREWS	N/A	1. 60 N•M [ 44 FT-LB ] 2. LOOSEN CAPSCREWS 3. 70 N•M [ 52 FT-LB ] 4. ADVANCE 60 DEGREES

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INJECTOR

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PART/MATERIAL/COLOR

LENGTH

TORQUE VALUE IN NM [ FT-LB ]

INJECTOR HOLD DOWN CLAMP CAPSCREWS

N/A

10 N•M [ 89 IN-LB ]

CRANKSHAFT

PART/MATERIAL/COLOR

LENGTH

TORQUE VALUE IN NM [ FT-LB ]

MAIN BEARING CAP CAPSCREWS

N/A

50 N•M [ 37 FT-LB ]

PART/MATERIAL/COLOR

LENGTH

TORQUE VALUE IN NM [ FT-LB ]

MAIN BEARING CAPSCREWS	128 MM [5 IN]	1. 50 N•M [ 37 FT-LB ] 2. 95 N•M [ 70 FT-LB ] 3. ROTATE 60 DEGREES
MAIN BEARING CAPSCREWS	135 MM [5.3 IN]	1. 170 N•M [ 125 FT-LB ] 2. LOOSEN ALL CAPSCREWS 3. 50 N•M [ 37 FT-LB ] 4. ROTATE 120 DEGREES

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OIL COOLER

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PART/MATERIAL/COLOR

LENGTH

TORQUE VALUE IN NM [ FT-LB ]

OIL COOLER CAPSCREWS

N/A

1. 15 N•M [ 11 FT-LB ] 2. 33 N•M [ 24 FT-LB ]

 

 

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ROCKER LEVER

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PART/MATERIAL/COLOR

LENGTH

TORQUE VALUE IN NM [ FT-LB ]

ROCKER LEVER PEDESTALL CAPSCREWS	N/A	65 N•M [ 48 FT-LB ]
ENGINE BRAKE OIL SUPPLY CAPSCREWS ON INTAKE ROCKER LEVERS 1 AND 4	N/A	65 N•M [ 48 FT-LB ]
EXHAUST ROCKER LEVER CAPSCREWS	N/A	65 N•M [ 48 FT-LB ]
PEDESTAL CAPSCREWS IN CYLINDERS 2, 3, 5 & 6 INTAKE ROCKER PEDESTALS	N/A	65 N•M [ 48 FT-LB ]
THREADED SPACERS INTO THE CYLINDER HEAD	N/A	24 N•M [ 212 IN-LB ]
ROCKER LEVER LOCK NUT	N/A	24 N•M [ 212 IN-LB ]