Centinel System – Repair Manual – 001-054   Piston and Connecting Rod Assembly

WARNING  To reduce the possibility of personal injury, reduce the possibility of 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. Reduce the possibility of inhalation of vapors, ingestion, and prolonged contact with used engine oil. 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.

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

WARNING  This component weighs 23 kg [50 lb] or more. To reduce the possibility of personal injury, use a hoist or get assistance to lift this component.

• Drain the lubricating oil. Refer to Procedure 007-037.
• Drain the cooling system. Refer to Procedure 008-018.
• Remove the lubricating oil pan. Refer to Procedure 007-025.
• Remove the lubricating oil suction tube. Refer to Procedure 007-035.
• Remove the block stiffener plate. Refer to Procedure 001-089.
• Remove the piston cooling nozzles. Refer to Procedure 001-046.
• Remove the connecting rod cap. Refer to Procedure 001-005.
• Remove the cylinder head. Refer to Procedure 002-004.

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

WARNING  Some solvents are flammable and toxic. Read the manufacturer’s instructions before using.

CAUTION  Do not use emery cloth or sandpaper to remove carbon from the cylinder liners. Aluminum oxide or silicon particles from emery cloth or sandpaper can cause serious engine damage. Do not use any abrasives in the ring travel area. The cylinder liner can be damaged.

Use a fine fibrous, abrasive pad such as Scotch-Brite™ 7448, Part Number 3823258, or equivalent, and solvent to remove the carbon.

Install two connecting rod guide pins, Part Number 3376038.

Use a T-handle piston pusher to push the connecting rod away from the crankshaft.

Push the connecting rod until the piston rings are outside of the top of the cylinder liner.

Remove the upper connecting rod bearing.

Mark the cylinder number and the letter U (upper) on the flat surface of the bearing tang.

Use both hands to remove the piston and connecting rod assembly.

The piston and connecting rod assemblies must be installed in the same cylinder they were removed from to provide for proper fit of worn mating surfaces if parts are reused.

Use a tag to mark the cylinder number from which each piston and connecting rod assembly was removed.

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

A unique number (not cylinder number) is stamped on the connecting rod and matching connecting rod cap. When the connecting rods and connecting rod cap are installed in the engine, the numbers on the connecting rod and cap must match and be installed on the same side (the exhaust side) of the engine.

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

CAUTION  Do not use a hammer to remove the piston pins. The piston can distort, causing it to seize in the liner.

If the piston pin can not be easily removed by hand, place the piston and connecting rod assembly in a container of water. Heat the piston in boiling water for 15 minutes.

Use a blunt tool to push the piston pin from the piston and connecting rod assembly.

CAUTION  When the piston pin is removed from an articulated piston, the skirt will separate from the crown. Use care to prevent damage to the piston.

If they are to be reused, mark the number of the cylinder that the piston, crown, skirt, and pin were removed from on the parts to make sure they are installed in the correct cylinder.

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

CAUTION  Do not use a hammer to remove the piston pins. The piston can distort, causing it to seize in the liner.

If the piston pin can not be easily removed by hand, place the piston and connecting rod assembly in a container of water. Heat the piston in boiling water for 15 minutes.

Use a blunt tool to push the piston pin from the piston and connecting rod assembly.

The piston and connecting rod assemblies must be installed in the same cylinder they were removed from to provide for proper fit of worn mating surfaces if parts are reused.

Use a tag to mark the cylinder number from which each piston and connecting rod assembly was removed.

All pistons (bushed and nonbushed) must be properly lubricated prior to assembly.

For all pistons, use a clean, lint free cloth to apply a heavy film of 85W-140 gear oil with EP additive to the following locations:

• Piston pin bore inside diameter in the piston crown
• Piston pin bore inside diameter in the piston skirt
• Rod bushing inside diameter
• Piston pin.

Assemble the piston crown into the piston skirt.

CAUTION  The retainer snap ring must be seated completely in the piston pin groove to prevent engine damage during engine operation.

It is not necessary to heat the articulated pistons before assembly. The piston pin is slip fitted.

The crown and skirt can only be assembled in one position.

Install a new snap ring into one piston pin bore of each piston skirt.

If the pistons are being reused, the crown, skirt, and pin must be matched as they were when they were removed.

Position the skirt over the piston crown.

Align the pin bore of the connecting rod with the pin bore of the piston skirt and crown, and install the piston pin.

On articulated pistons, make sure the locking tang on the connecting rod is on the same side as the cooling nozzle notch in the piston skirt and opposite the deep valve pocket on the crown.

CAUTION  The snap ring must be seated completely in the piston groove to prevent engine damage during engine operation.

Install a new snap ring into the piston pin bore.

Install piston rings. Refer to Procedure 001-047.

CAUTION  The retainer snap ring must be seated completely in the piston pin groove to prevent engine damage during engine operation.

Install a new snap ring into one piston pin bore of each single-piece piston.

If the pistons are being reused, the single-piece piston and pin must be matched as they were when they were removed.

CAUTION  Generously coat both single-piece piston pin bores with a heavy weight gear oil, such as 85W-140 EP, when assembling single-piece pistons. Also lubricate the connecting rod bushing. If gear oil is not available, Lubriplate, Part Number 3163086, is permissible. Failure to adequately lubricate the pin joint can result in extensive engine damage, particularly with single-piece pistons.

Use clean 85W-140 oil to coat the piston pin.

The single-piece piston requires a drilled connecting rod and a drilled upper connecting rod bearing to lubricate the pin joint. Do not assemble a single-piece piston with a non-drilled connecting rod nor a non-drilled connecting rod bearing. Make certain when assembling a single-piece piston that the lubricating hole in the connecting rod bearing lines up with lubricating hole in the connecting rod.

On single-piece pistons, the locking tang on the connecting rod is to be on the opposite side of the deep valve pocket.

Install the piston pin.

CAUTION  The snap ring must be seated completely in the piston groove to prevent engine damage during engine operation.

Install a new snap ring into the piston pin bore.

Install the piston rings. Refer to Procedure 001-047.

Immerse the piston in a container of clean 15W-40 oil.

Remove the piston from the container. Let the excess oil drain from the piston.

Use piston ring compressor, Part Number 3164846, to compress the rings.

The cylinder block and all parts must be clean before assembly.

Inspect the cylinder liners for reuse. Refer to Procedure 001-028.

Use a clean, lint-free cloth to clean the connecting rods and bearing shells.

Do not lubricate the backside of the bearing shells. The operating clearance of the bearing will be reduced and the bearing can be damaged during engine operation.

If new bearings are not used, the used bearings must be installed on the same connecting rod from which they were removed.

Install the upper bearing shell into the connecting rod.

The tang of the bearing shell (2) must be in the slot of the cap (1). The end of the bearing shell must be even with the cap mounting surface.

Use Lubriplate™ 105, Part Number 3163086, or equivalent, to coat the entire inside circumference of the bearing shell.

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

Install connecting rod guide pins, Part Number 3163097.

Use the compressor drive or barring device to rotate the crankshaft so the connecting rod journal of the connecting rod being installed is at bottom dead center.

CAUTION  Failure to align the deep valve pocket and the piston skirt cooling nozzle notch correctly will result in extensive engine damage.

Align the piston crown deep valve pocket on the exhaust side of the engine, and the piston skirt cooling nozzle notch to the intake side of the engine.

If the deep valve pocket and the piston skirt cooling nozzle notch are not on opposite sides, the piston and connecting rod assembly are not assembled correctly. Disassemble the piston and connecting rod and assemble correctly.

Insert the connecting rod through the cylinder liner until the ring compressor contacts the top of the liner.

Both articulated pistons and single-piece pistons have an arrow on the top of the piston crown, which will point to the front of the engine, when the piston is installed properly.

CAUTION  Do not use a metal drift to push the piston into the cylinder liner. The piston rings or cylinder liner can be damaged.

Hold the ring compressor against the cylinder liner. Push the piston through the ring compressor and into the cylinder liner. Push the piston until the top ring is completely in the cylinder liner.

If the piston does not move freely, remove the piston and inspect for broken or damaged rings.

Use the nylon guide pins to align the connecting rod with the crankshaft while pushing the piston and connecting rod assembly into place.

Remove the nylon guide pins.

NOTE: When rebuilding an engine with single-piece pistons that was originally built with articulated pistons, stamp the dataplate with the letters SP. This will alert future repair locations that this engine has been rebuilt with single-piece pistons.

• Install the connecting rod cap. Refer to Procedure 001-005.
• Install the piston cooling nozzles. Refer to Procedure 001-046.
• Install the block stiffener plate. Refer to Procedure 001-089.
• Install the lubricating oil suction tube. Refer to Procedure 007-035.
• Install the lubricating oil pan. Refer to Procedure 007-025.
• Install the cylinder head. Refer to Procedure 002-004.
• Prime the lubricating oil system. Refer to Procedure 007-037.
• Fill the coolings system with coolant. Refer to Procedure 008-018.
• Fill the engine with clean lubricating oil. Refer to Procedure 007-037.
• Operate the engine to normal operating temperature and check for leaks.