Cummins ISX11.9 CM2250 – Service Manual 003-009   Rocker Lever Assembly

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 EGR crossover tube. Refer to Procedure 011-070 in Section 11.
• Remove the crankcase breather. Refer to Procedure 003-001 in Section 3.
• Remove the rocker lever cover. Refer to Procedure 003-011 in Section 3.
• Remove the engine brakes, if equipped. Refer to Procedure 020-024 in Section 20.
• Remove the push rods or push tubes. Refer to Procedure 004-014 in Section 4.

NOTE: There are two rocker lever shaft assemblies: front and rear. This includes unique exhaust and intake rocker levers for the front and rear assemblies.

To ease in the lifting of each assembly, flip all six rocker levers so the adjusting screws are pressed down against each of the rocker lever supports.

Set a wooden dowel rod on the rocker levers. Secure the dowel rod to the rocker lever supports with rubber bands or a string.

Loosen, but do not remove, the six rocker shaft capscrews. The capscrews hold the rocker lever assemblies together.

Grasp hold of the assembly by the rocker levers and shaft, then lift them from the engine. The shafts can lift out of the supports.

Repeat the process to remove the rear rocker lever assembly.

Mark each rocker lever, shaft, and support with its relative position in the engine.

The rocker lever assemblies must be installed in the same positions from which they were removed.

Remove the rocker lever shaft capscrews and retaining clamps.

Remove each of the retaining rings and washers from the front and the rear of the rocker lever shaft.

Remove the rocker levers, rocker lever supports, and rocker lever shaft spacers from the shaft.

Remove the locknuts and the adjusting screws from each rocker lever.

The adjusting screw can only be removed and installed from the bottom of the lever.

WARNING  When using a steam cleaner, wear safety glasses or a face shield, as well as protective clothing. Hot steam can cause serious personal injury.

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 steam or solvent to clean the parts.

Dry with compressed air.

Be sure to blow out the oil passages.

Inspect the rocker levers for cracks, excessive pitting, or unusual wear.

Inspect the adjusting screws and locknuts for damaged threads.

Inspect the adjusting screw threads in the rocker levers for damaged threads.

Verify that there is a sealing ball (1) installed in the oil drilling at the end of the lever.

The ball must not protrude past the nose of the lever.

Measure each rocker lever bushing bore inside diameter.

Rocker Lever Inside Diameter (Bushing Installed)

Inspect the rocker lever shafts for pitting, scoring, or other damage.

Verify that the cup plugs are installed at each end of the shaft. The cup plugs must not protrude past the end of the shaft.

Measure each rocker lever shaft outside diameter.

Rocker Lever Shaft Outside Diameter

If worn or damaged parts are found, or the rocker lever bushings or shafts are not within the specifications given, the rocker lever assemblies must be rebuilt.

Inspect the valve rocker lever foot for wear, cracks, or other damage.

If the retaining clip for the rocker lever foot is broken, the rocker lever can be reused; however, care must be taken when installing the foot and lever on the crosshead.

NOTE: If the retaining clip is broken, check the oil pan to verify the rocker lever foot did not fall down into the oil pan.  Also check to make sure it is has not fallen onto the camshaft.

If wear, cracks, or other damage is found, the rocker lever must be replaced.

Use crack detection kit, Part Number 3375432, to inspect the rocker lever supports for cracks or cavitation damage.

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

Use crack detection cleaner, Part Number 3375433, to clean the rocker levers and shaft supports.

Dry with compressed air.

Use crack detection penetrant, Part Number 3375435, to spray the rocker levers and shaft supports.

NOTE: Do not dry with compressed air.

Allow the penetrant to dry for 15 minutes.

Remove the excess penetrant with a dry cloth.

Use crack detection developer, Part Number 3375434, to spray the rocker levers and shaft supports.

Inspect the levers and supports.

Cracks will appear as a solid, bright line.

Cavitation damage in the casting will appear as a small round mark.

If cracks or cavitation damage is found, the part must be replaced.

CAUTION  There are two rocker lever shaft assemblies: front and rear. Be sure to position the rocker lever support assemblies in their proper location. If the engine is equipped with a compression brake, the proper rocker lever support must be located at the center of the cylinder head, rocker lever shaft positions 3 and 4, to supply the compression brake with oil. Failure to properly position the rocker lever supports will prevent the compression brake from operating.

NOTE: The longer rocker lever is the exhaust lever and the shorter rocker lever is the intake lever.

NOTE: These steps are for the assembly of the front rocker lever support assembly.

The front rocker lever shaft assembly must be assembled such that the Number 1 intake lever is located at the front of the shaft assembly on the outside and the Number 3 exhaust lever is located at the back of the shaft assembly on the outside.

Install the retaining ring into the groove on the front of the rocker lever shaft.

NOTE: Rocker lever shaft orientation is not required.

Lubricate the shaft with clean 15W40 engine oil.

Install the washer from the rear of the shaft and slide it to the front against the retaining ring.

Install the rocker levers in the correct sequence, as illustrated.

NOTE: The rocker levers must be installed so they will be in the same position in the engine as when they were removed.

Install one of the two shaft center supports without the oil supply drilling on the shaft.

Install the retaining block and capscrew through the center support.

Install the remaining levers, supports, and spacers with the intake (l) and exhaust (E) valve levers in the correct position, as illustrated.

NOTE: For the front assembly, the support with the oil supply drilling must be located in the rear support position, over cylinder Number 3.

Install the washer and retaining ring onto the rear of the shaft.

NOTE: Verify that both the front and rear retaining rings are seated properly into the grooves on the shaft.

NOTE: This step is for the assembly of the rear rocker lever support assembly.

Repeat the same process for the rear rocker lever assembly, using the sequence shown here.

The rear rocker lever shaft assembly must be assembled such that the Number 4 exhaust lever is located at the front of the shaft assembly on the outside and the Number 6 intake lever is located at the back of the shaft assembly on the outside.

NOTE: For the rear assembly, the support with the oil supply drilling must be located in the front support position, over cylinder Number 4.

NOTE: Verify that both the front and rear retaining rings are seated properly into the grooves on the shaft.

The rocker lever assemblies must be installed in the engine so they are in the same positions from which were removed.

Install the rocker lever shaft assemblies onto the cylinder head. Be sure that rocker lever shaft supports Number 3 and Number 4 have the oil supply drillings for the engine brake.

NOTE: Hand-tighten the mounting capscrews at this time. The rocker lever side clearance must be adjusted before the capscrews are tightened to their final torque value.

Rocker Lever Installation Side Clearance

Install a 0.188 mm [0.007 in] feeler gauge between the Number 1 intake lever and the Number 1 support for the Number 1 cylinder.

Push or use a hammer to tap the Number 1 rocker lever support toward the front of the engine.

Tighten the Number 1 support mounting capscrew.

NOTE: This is not the final torque value.

Install a 0.500 mm [0.020 in] feeler gauge between the Number 2 intake lever and the Number 2 support for the Number 2 cylinder.

Push or use a hammer to tap the Number 2 support toward the front of the engine.

Tighten the Number 2 support mounting capscrew.

NOTE: This is not the final torque value.

Install a 0.500 mm [0.020 in] feeler gauge between the Number 3 intake lever and the Number 3 support for the Number 3 cylinder.

Push or use a hammer to tap the Number 3 support toward the front of the engine.

Tighten the Number 3 mounting capscrews.

NOTE: This is not the final torque value.

Check the clearance between the Number 3 support and the exhaust lever for the Number 3 cylinder.  There should be a nominal clearance of 0.188 mm [0.007 in].

Tighten the Number 1, 2, and 3 support capscrews to their final torque.

Install a 0.188 mm [0.007 in] feeler gauge between the Number 4 exhaust lever and the Number 4 support for the Number 4 cylinder.

Push or use a hammer to tap the Number 4 rocker lever support toward the front of the engine.

Tighten the Number 4 support mounting capscrew

NOTE: This is not the final torque value.

Install a 0.500 mm [0.020 in] feeler gauge between the Number 5 exhaust lever and the Number 5 support for the Number 5 cylinder.

Push or use a hammer to tap the Number 5 support toward the front of the engine.

Tighten the Number 5 support mounting capscrew.

NOTE: This is not the final torque value.

Install a 0.500 mm [0.020 in] feeler gauge between the Number 6 exhaust lever and the Number 6 support for the Number 6 cylinder.

Push or use a hammer to tap the Number 6 support toward the front of the engine.

Tighten the Number 6 support mounting capscrew.

NOTE: This is not the final torque value.

Check the clearance between the Number 6 support and the intake lever for the Number 6 cylinder.  There should be a nominal clearance of 0.188 mm [0.007 in].

Tighten the Number 4, 5, and 6 support capscrews to their final torque.

Check the front and rear assemblies for correct clearance. Check the support capscrews for the correct torque value.

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 push rods or push tubes. Refer to Procedure 004-014 in Section 4.
• Install the engine brakes, if applicable. Refer to Procedure 020-024 in Section 20.
• Adjust the overhead. Refer to Procedure 003-004 in Section 3.
• Install the rocker lever cover. Refer to Procedure 003-011 in Section 3.
• Install the crankcase breather. Refer to Procedure 003-001 in Section 3.
• Install the EGR crossover tube. Refer to Procedure 011-070 in Section 11.
• Connect the batteries. Refer to the OEM service manual.
• Operate the engine to normal operating temperature and check for proper operation.