Ensure the backs of the bearing shells are completely clean and dry.
To make sure I give you the most accurate data for your specific build, could you tell me: What is your Engine Serial Number (ESN) Are you using OEM Cummins bolts or an aftermarket brand like Are you working on an older or a newer single-cam
Common safe approach (for non-yield re-usable bolts, when manual absent):
| Component | Stage 1 | Stage 2 | Stage 3 | Stage 4 | Stage 5 | | :--- | :--- | :--- | :--- | :--- | :--- | | | 80 ft-lbs | 140 ft-lbs | Loosen 360° | 80 ft-lbs | +105° | | Main Bolt (New) | 150 ft-lbs | None | Loosen 360° | 150 ft-lbs | +90° | cummins isx main and rod bearings torque specs new
Use a high-quality engine assembly lube on the bearing faces, but only clean engine oil on the bolt threads and bolt seats.
Cummins publishes model- and year-specific torque and bolt-stretch procedures in the official service manual and bolt specification tables. Because ISX variants and fastener types changed over production years, always confirm torque and whether bolts are torque-to-yield by checking the engine serial number and the Cummins service manual or official parts documentation before final assembly.
If you want, provide your engine serial or model year and I will fetch the exact factory torque and angle specs for your ISX (recommended). Ensure the backs of the bearing shells are
Before installing new bearings, ensure the main bearing saddles are not distorted.
For used bolts, inspect for any signs of stretching or damage. Many professional guides recommend using new head and rod bolts for every major rebuild. Cummins ISX Torque Specs: Main & Rod Bearings, Oil Pump
Remove all traces of Plastigage. Clean the back of the bearing shells and the saddle/cap bores; these surfaces must be completely dry to prevent the bearing from spinning. Apply a generous amount of high-quality engine assembly lube to the front face (running surface) of the bearings and the crankshaft journals before final assembly. Summary Reference Table Fastener Component Initial Torque Intermediate Torque Final Torque Angle Turn 150 N·m [111 lb-ft] 300 N·m [221 lb-ft] Loosen & repeat 300 N·m + 90° Rod Cap Bolts 95 N·m [70 lb-ft] 135 N·m [100 lb-ft] 180 N·m [133 lb-ft] + 60° Because ISX variants and fastener types changed over
| Component | Fastener Type | Torque Procedure | | :--- | :--- | :--- | | (Engine SN up to 7,901,2120, "USA" block) | Mains | 110 ft-lbs + 180° (Torque-to-Yield) | | Main Bearing Cap Bolts (Engine SN after 7,901,2120, "MEX" block) | Mains | 300 ft-lbs + 90° (Torque-to-Yield) | | Connecting Rod Bolts (USED) | Used Rod Bolt | 52 ft-lbs + 60° | | Connecting Rod Bolts (NEW) | New Rod Bolt | 30 ft-lbs → LOOSEN → 52 ft-lbs + 60° |
Main bearing cap tightening sequence:
Ensure the backs of the bearing shells are completely clean and dry.
To make sure I give you the most accurate data for your specific build, could you tell me: What is your Engine Serial Number (ESN) Are you using OEM Cummins bolts or an aftermarket brand like Are you working on an older or a newer single-cam
Common safe approach (for non-yield re-usable bolts, when manual absent):
| Component | Stage 1 | Stage 2 | Stage 3 | Stage 4 | Stage 5 | | :--- | :--- | :--- | :--- | :--- | :--- | | | 80 ft-lbs | 140 ft-lbs | Loosen 360° | 80 ft-lbs | +105° | | Main Bolt (New) | 150 ft-lbs | None | Loosen 360° | 150 ft-lbs | +90° |
Use a high-quality engine assembly lube on the bearing faces, but only clean engine oil on the bolt threads and bolt seats.
Cummins publishes model- and year-specific torque and bolt-stretch procedures in the official service manual and bolt specification tables. Because ISX variants and fastener types changed over production years, always confirm torque and whether bolts are torque-to-yield by checking the engine serial number and the Cummins service manual or official parts documentation before final assembly.
If you want, provide your engine serial or model year and I will fetch the exact factory torque and angle specs for your ISX (recommended).
Before installing new bearings, ensure the main bearing saddles are not distorted.
For used bolts, inspect for any signs of stretching or damage. Many professional guides recommend using new head and rod bolts for every major rebuild. Cummins ISX Torque Specs: Main & Rod Bearings, Oil Pump
Remove all traces of Plastigage. Clean the back of the bearing shells and the saddle/cap bores; these surfaces must be completely dry to prevent the bearing from spinning. Apply a generous amount of high-quality engine assembly lube to the front face (running surface) of the bearings and the crankshaft journals before final assembly. Summary Reference Table Fastener Component Initial Torque Intermediate Torque Final Torque Angle Turn 150 N·m [111 lb-ft] 300 N·m [221 lb-ft] Loosen & repeat 300 N·m + 90° Rod Cap Bolts 95 N·m [70 lb-ft] 135 N·m [100 lb-ft] 180 N·m [133 lb-ft] + 60°
| Component | Fastener Type | Torque Procedure | | :--- | :--- | :--- | | (Engine SN up to 7,901,2120, "USA" block) | Mains | 110 ft-lbs + 180° (Torque-to-Yield) | | Main Bearing Cap Bolts (Engine SN after 7,901,2120, "MEX" block) | Mains | 300 ft-lbs + 90° (Torque-to-Yield) | | Connecting Rod Bolts (USED) | Used Rod Bolt | 52 ft-lbs + 60° | | Connecting Rod Bolts (NEW) | New Rod Bolt | 30 ft-lbs → LOOSEN → 52 ft-lbs + 60° |
Main bearing cap tightening sequence:
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