Cummins N14 STC, Celect, Celect Plus – Service Manual 002-001   Crosshead

WARNING  Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. To reduce the possibility of arcing, remove the negative (-) battery cable first and attach the negative (-) battery cable last.

• Disconnect the batteries. Refer to the OEM service manual.
• Remove the rocker lever cover. Refer to Procedure 003-011 in Section 3.
• Remove the rocker lever assembly. Refer to Procedure 003-009 in Section 3.

Remove the crossheads. Make sure to mark them appropriately so they can be installed in the same location and orientation during the installation procedure.

NOTE: Excessive crosshead wear can result if the crossheads are not installed in their original locations. The larger hole on the underside of the crosshead must be oriented toward the exhaust side of the engine.

WARNING  When using solvents, acids, or alkaline materials for cleaning, follow the manufacturer’s recommendations for use. Wear goggles and protective clothing to reduce the possibility of personal injury.

WARNING  Wear appropriate eye and face protection when using compressed air. Flying debris and dirt can cause personal injury.

Use solvent to clean the crosshead.

Dry the components with compressed air.

Inspect the rocker lever contact pad for wear, cracks, or other damage.

Inspect the valve stem contact areas for damage.

Measure both valve stem pocket depths from the valve stem pocket to the rocker pad face (1).

Stem Pocket to Pad Face Depth

On a given crosshead, the stem pocket to pad bore dimension (1) on one end must fall within 0.51 mm [0.020 in] of the dimension (2) on the opposite end.

In a cylinder head assembly, the crosshead to valve spring retainer clearance must be a minimum of 0.51 mm [0.020 in].

NOTE: If damaged components are found or if the stem bore or pocket depth is not within specifications, the components must be replaced. If cracks are suspected, complete a magnetic crack inspection. Reference the Alternative Repair Manual, Bulletin 3379035.

Install the valve crossheads in their original location and orientation.

Lubricate the valve stems with clean 15W-40 oil.

Use a wire gauge to check the clearance between the crosshead and the valve spring retainer. The clearance must be a minimum of 0.51 mm [0.020 in].

NOTE: The large pocket is toward the exhaust side.

WARNING  Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. To reduce the possibility of arcing, remove the negative (-) battery cable first and attach the negative (-) battery cable last.

• Install the rocker lever assembly. Refer to Procedure 003-009 in Section 3.
• Adjust the valves and injectors. Refer to Procedure 003-004 in Section 3.
• Install the rocker lever cover. Refer to Procedure 003-011 in Section 3.
• Connect the batteries. Refer to the OEM service manual.
• Operate the engine and check for leaks.