Cummins N14 STC, Celect, Celect Plus – Service Manual 001-054   Piston and Connecting Rod Assembly

WARNING  Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. Wear goggles and protective clothing to reduce the possibility of serious personal injury.

WARNING  To reduce the possibility of personal injury, avoid direct contact of hot oil with your skin.

WARNING  Some state and federal agencies have determined that used engine oil can be carcinogenic and cause reproductive toxicity. Avoid inhalation of vapors, ingestion, and prolonged contact with used engine oil. If not reused, dispose of in accordance with local environmental regulations.

WARNING  Coolant is toxic. Keep away from children and pets. If not reused, dispose of in accordance with local environmental regulations.

WARNING  Do not remove the pressure cap from a hot engine. Wait until the coolant temperature is below 50°C [120°F] before removing the pressure cap. Heated coolant spray or steam can cause personal injury.

• Disconnect the batteries. Refer to the OEM service manual.
• Drain the lubricating oil. Refer to Procedure 007-037 in Section 7.
• Drain the cooling system. Refer to Procedure 008-018 in Section 8.
• Remove the rocker lever covers. Refer to Procedure 003-011 in Section 3.
• Remove the engine brakes, if equipped. Refer to Procedure 020-024 in Section 20.
• Remove the rocker lever assemblies. Refer to Procedure 003-009 in Section 3.
• Remove the rocker lever housings. Refer to Procedure 003-013 in Section 3.
• Remove the injectors. Refer to Procedure 006-026 in Section 6.
• Remove the cylinder heads. Refer to Procedure 002-004 in Section 2.
• Remove the lubricating oil pan. Refer to Procedure 007-025 in Section 7.
• Remove the piston cooling nozzles. Refer to Procedure 001-046 in Section 1.

WARNING  Wear appropriate eye and face protection when using wire brushes to remove carbon from the cylinder block. Flying debris and dirt can cause personal injury. Also, make sure the wire brush is rated for the rpm being used if the brush is motor driven.

CAUTION  Do not use abrasive paper to remove the carbon ring. Small particles of abrasive material will cause severe engine damage.

Plug the overhead oil rifle push tube cavities and coolant passages in the cylinder block, and use a rotary wire brush to remove the carbon ring from the top of the cylinder liner. Use a scraper that has an aluminum blade, if a rotary wire brush is not available.

Use lint-free paper to remove all the broken wire bristles and loose carbon from the cylinders.

Use the accessory drive pulley to rotate the crankshaft to position two of the connecting rods at bottom-dead-center.

NOTE: Do not remove the capscrews.

Loosen the connecting rod capscrews.

Hit the connecting rod capscrews with a rubber hammer to loosen the connecting rod caps from the dowels.

Remove the capscrews and the rod cap.

Remove the bearing shell from the rod cap and mark the cylinder number and the letter “L” in the flat surface of the bearing tangs.

Install two connecting rod guide pins, Part Number 3375601.

Use a mallet to push the rod away from the crankshaft.

NOTE: Push the connecting rod away from the crankshaft, cover the crankshaft rod journal, and push the connecting rod until the piston rings are outside of the top of the cylinder liner.

Remove the piston and connecting rod assembly.

NOTE: The piston crown, skirt, and the connecting rod assemblies must be installed in the same cylinder number they were removed from to make sure proper fit of worn mating surfaces, if parts are used again. Also, the piston skirt and crown must be reinstalled together.

Use a tag to mark the cylinder number that each piston and connecting rod assembly was removed from. Make sure to mark both the skirt and crown on the piston.

NOTE: The piston crown must have the cylinder numbers stamped on the piston top toward the camshaft side of the engine. The skirt must also be stamped so it can be matched with the piston crown.

Remove the upper rod bearing.

Mark the cylinder number and the letter “U” in the flat surface of the bearing tang.

Place the connecting rod and piston assemblies in a stand to protect them from damage.

CAUTION  Do not over-expand the piston ring’s maximum dimension. The piston ring will break.

Use piston ring expander, Part Number 3823871, to remove the piston rings.

Place a tag on the rings and record the cylinder number of the piston on the tag for future reference (if required). Refer to Procedure 001-047 in Section 1.

Use internal snap ring pliers to remove the snap rings from both sides of the piston.

The piston pin must be removed at room temperature by using a blunt tool to manually push the pin from the rod assembly.

NOTE: Make sure the piston and connecting rod assembly are correctly marked.

If the piston pin can not be removed at room temperature, it is acceptable to put the piston in 66°C [151°F] water for 15 to 30 minutes, then manually remove the piston pin with a blunt tool.

Manually remove the piston skirt from the crown. Extreme caution must be taken to prevent damage to both the crown and skirt.

Clean the pistons. Refer to Procedure 001-043 in Section 1.

Inspect the pistons. Refer to Procedure 001-043 in Section 1.

Inspect the piston rings for damage and wear analysis. Refer to Procedure 001-047 in Section 1.

Inspect the connecting rods. Refer to Procedure 001-014 in Section 1.

Align the piston skirt and crown.

Install a new snap ring in one of the snap ring grooves of the piston pin bore on each piston.

Heat the pistons in hot tap water, 66°C [151°F], for 15 to 30 minutes.

Use clean 15W-40 lubricating oil to lubricate the connecting rod piston pin bore and the piston pin.

Remove the piston from the water and lubricate the piston pin bore with clean 15W-40 lubricating oil.

Align the pin bore of the connecting rod with the pin bore of the piston and install the piston pin. Do not use a hammer to install the piston pin. The piston will be damaged.

NOTE: The cylinder number of the piston top (1) must be toward the bearing tang (2) side of the connecting rod.

The pin must easily assemble without force. If not, inspect the pin, connecting rod bushing, and piston for damage, dirt, and poor lubrication.

Install a new snap ring in the second piston pin bore snap ring groove. The snap ring must be seated completely in the snap ring groove.

CAUTION  Do not over-expand the piston rings maximum dimension. The piston ring will break.

Use piston ring expander, Part Number 3823871, to install new piston rings with the part number, mark, or the word “TOP” toward the top of the piston.

NOTE: The oil control ring is symmetrical and can be installed in either orientation.

The ring gap of each ring must not be aligned with the piston pin or with any other ring.

A cross-sectioned view of an oil control ring is illustrated. The two-piece oil control ring must be installed with the expander rig gap 180 degrees from the gap of the oil ring.

Install the upper bearing shell in the connecting rod. If used bearing shells are to be installed, each bearing shell must be installed in its original location.

NOTE: The tang (1) of the bearing shell must be in the slot (2) of the rod.

Use clean Lubriplate® 105, or equivalent, to lubricate the bearing shell.

Apply a heavy film of clean 15W-40 lubricating oil to the liner.

Lubricate the piston and the ring assembly by hand with clean 15W-40 lubricating oil. Dipping is okay, but draining is very difficult because the piston does not have drain holes. If dipping, only dip up to the pin bore, then hand lubricate it and the remaining skirt.

Install connecting rod guide pins, Part Number 3375601.

Use piston ring compressor, Part Number 3822736, to compress the piston rings.

Use the accessory drive pulley to rotate the crankshaft.

Rotate the crankshaft to position the journal for the connecting rod at bottom-dead-center.

CAUTION  To reduce the possibility or piston damage, do not use a metal object to push the piston into the liner.

The tang of the connecting rod must be toward the camshaft side of the cylinder block.

CAUTION  Do not use a hammer or its equivalent to install the piston into the cylinder liner. The piston rings can be damaged.

Install the connecting rod into the cylinder liner and push the piston down. If the piston does not move freely, remove the piston.

Inspect for broken or damaged rings.

When installing the connecting rod, pay close attention to make sure the rod is aligned with the crankshaft rod journal. If the rod is misaligned, it can bind or scrape the crankshaft connecting rod journal side walls.

Use the guide pins to pull the connecting rod against the crankshaft.

Remove the guide pins.

Install the bearing in the connecting rod cap.

The tang (2) of the bearing must be in the slot (1) of the connecting rod cap.

Lubricate the bearing shell with Lubriplate® 105, or equivalent. Lubricate the connecting rod capscrew threads and the washer face with 15W-40 lubricating oil.

CAUTION  The connecting rod cap alpha characters must match the alpha characters on the connecting rod and must be installed with the characters aligned to prevent damage to the connecting rods and crankshaft. The locking tang of the connecting rod cap must be toward the camshaft side of the cylinder block.

Install the connecting rod caps and capscrews.

The connecting rod has changed on the 1994 Certification Level engine to accommodate the increased loading of the articulated pistons. The torquing procedure for the connecting rod capscrews has also changed. The new torque specification is 129 N•m [95 ft-lb] plus 60 degrees ± 5 degrees.

To facilitate this new torquing procedure, the torque angle socket gauge, Part Number 3824520, was developed.

The torque angle socket is marked with a zero (start) point, a specification window, and an Out-of-Limits (OOL) line.

The tightening procedure is to pre-tighten both of the capscrews to 129 N•m [95 ft-lb].

With the socket on the capscrew, draw a line from the zero (start) point across the capscrew head to a point on the rod cap.

This line is the gauge line for the angle portion of the specification (60 degrees ± 5 degrees).

With the “0” line on the socket gauge aligned with the line on the connecting rod cap, tighten the capscrew.

With the socket gauge in position, check to see if the fixed line (on the connecting rod cap) is within the window on the gauge.

If the fixed line is between the “0” line and the “Out-of-Limits (OOL)” line, tighten or loosen the capscrew until the line is within the window.

If the fixed line is past the “OOL” line, replace the capscrew and repeat the tightening sequence.

Measure the connecting rod side clearance.

Connecting Rod Side Clearance

NOTE: If the side clearance does not meet these specifications, do the following.

Remove the rod caps. Inspect the rod caps for dirt, damage, and correct bearings.

Install the connecting rod caps and tighten the connecting rod capscrews.

Measure the side clearance again.

NOTE: If the side clearance does not meet the specifications, the connecting rod must be replaced.

WARNING  Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. Wear goggles and protective clothing to reduce the possibility of serious personal injury.

CAUTION  The lubricating oil system must be primed before operating the engine after any internal engine repairs to avoid internal component damage.

• Install the piston cooling nozzles. Refer to Procedure 001-046 in Section 1.
• Install the lubricating oil pan. Refer to Procedure 007-025 in Section 7.
• Install the cylinder heads. Refer to Procedure 002-004 in Section 2.
• Install the rocker lever housings. Refer to Procedure 003-013 in Section 3.
• Install the injectors. Refer to Procedure 006-026 in Section 6.
• Install the rocker lever assemblies. Refer to Procedure 003-009 in Section 3.
• Adjust the valves and injectors. Refer to Procedure 003-004 in Section 3.
• Install and adjust the engine brakes, if equipped. Refer to Procedure 020-024 in Section 20.
• Install the rocker lever covers with their original reusable gasket if they are not damaged. Refer to Procedure 003-011 in Section 3.
• Prime and fill the lubricating system. Refer to Procedure 007-037 in Section 7.
• Fill the cooling system. Refer to Procedure 008-018 in Section 8.
• Connect the batteries. Refer to the OEM service manual.
• Operate the engine until it reaches a water temperature of 82°C [180°F], and check for coolant or lubricating oil leaks.