| Q: Why replace a connecting rod? | 8/6/2024 |
| A: In general you dont. There is a bushing on top that is replaceable and the rod bearings in the bottom are designed to be be replaced. Sometime when an engine spins a bearing or worse the rods can get damaged. Then you replace a rod. Remember that the rod and the cap are a matching assembly and must stay together. | |
Q: What is the Connecting Rod Bore ID for B Series engines and Cummins C Series engines? | 9/25/2024 |
| A: The Cummins Repair Manual says that the connecting rod bore ID with bearings should be 76.046mm MIN and 76.104mm MAX for C Series engines and 69.051mm MIN and 69.103mm MAX. If the rod is replaced, they nuts should be torqued and then the rod should be stamped according to what cylinder it is going in. | |
Q: What is the Connecting Rod nut torque spec for Cummins B Series engines and C Series engines? | 9/25/2024 |
| A: The Cummins Repair Manual says that the connecting rod torque spec is done in 3 steps. First is 20NM. Second is 80NM and Third is 120NM. | |
Q: Are there lighter connecting rods available for a Cummins 5.9 6BT engine? | 9/30/2024 |
| A: The Haynes Repair Manual discusses this topic, but unless you are going to drastically increase your maximum RPM, they shouldn't be necessary. This is not a small thing. It must be well thought out with a different camshaft and maybe other parts as well to do it right. | |