Cummins 4BT – Piston and Connecting Rod Assemblies – Installation

Install the bearing shells into both the connecting rod and the connecting rod cap. Make sure the tank on the bear­ing shells is in the slot of the connecting rod cap and connecting rod.

Position the rings.

Lubricate the cylinder bore with clean engine lubricating oil.

Position the connecting rod journal for the piston to be installed to bottom dead center (BDC).

Take care not to damage the cylinder wall when in­serting the connecting rod.

Lubricate the threads and underside of the connecting rod caps crew heads with engine lubricating oil.

Caution: The four digit number stamped on the rod and cap at the parting line must match and be installed on the
oil cooler side of the engine.
Install the connecting rod cap and capscrews to the con­necting rod.

12 mm, Torque Wrench
Alternately, tighten the two capscrews.

Measure the side clearance between the connecting rod and crankshaft.
Do not measure the clearance between the rod cap and crankshaft.
Side Clearance Limits 0.10 to 0.33 mm [0.004 to 0.013 inch]

Caution: The crankshaft must rotate freely.
Check for freedom of rotation as the connecting rod caps are installed. If the crankshaft does not rotate freely, check
the installation of the connecting rod bearings and the bearing size.
NOTE: If the connecting rod is not properly oriented (tang opposite the camshaft), it will contact the camshaft and lock the engine.