CMI-J8V2A-04
Service Bulletin Details
Public Details for: CMI-J8V2A-04
This is a representative communication from the cummins producing plant to possibly affected vehicle manufacturers regarding a potential issue with the #5 intake rocker pedestal cap screw not being fully torqued on a jake brake engine follo
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Models from 9999
9999 CUMMINS L9 |
L9 – Jake Brake #5 Intake rocker pedestal cap screw not fully torqued March 26, 2018 Confidential S1 S2 S3 S4 S5 S6 S7 Step 1 Identify The Problem Navistar SAP found ESN 74273427 was running rough and had high smoke 74273427 – Cap screw standing proud ESN: 74273427 OEM: Navistar SAP Model: L9 370 Hp with Jake brake Lineset: 2/16 Defect reported: 3/13 Hours/Miles: 2.2hrs / 2 miles Troubleshooting: • The Cummins Service Technician performed a cylinder cutout test with Insite to identify Cylinder 5 had an issue • After removing the valve cover, the #5 Intake rocker pedestal cap screw was found standing proud Repair: • Torqued the cap screw to 65Nm and the issue was resolved 2 S1 S2 S3 S4 S5 S6 S7 Step 2: Determine Possible Causes and Rank Their Importance Suspect causes 1. Inadequate repair completed at RMEP • The engine history was reviewed and found no issues with out of process, hot test or repairs 2. Incorrect torque applied by the rocker pedestal torque unit • Critical finding: A Quality torque over check found the #5 intake rocker pedestal cap screw was not fully torqued on a Jake Brake engine after the rocker pedestal torque unit 3 3 S1 S2 S3 S4 S5 S6 S7 Step 3: Take Short Term Action The product was contained and a clean point was established Dock closure 5439 on all Jake brake engines – (3/23) • Verify the #5 intake rocker pedestal cap screw is torqued to 65Nm #5I cap screw Reteach #5 intake on the Jake brake program – (3/23) • Quality verified the proper torque was applied after the change • ESNf 74291280 4 4 S1 S2 S3 S4 S5 S6 S7 Step 4: Determine the assignable cause(s) An error was made during the robot relocation teaching Video from 10/23 shows the c/s receiving torque Video from 11/11 shows the c/s not receiving torque On 3/23, maintenance reviewed a Jake brake engine run through the cycle • It was noted that robot 1 was torqueing cylinder #6 intake twice instead of moving to next step which is cylinder #5 intake • The engine received a pass status Reviewed video footage of the torque robot • October 23rd shows the 5I cap screw receiving torque • November 11th shows the 6I cap screw being torqued twice #5I cap screw #6I cap screw torqued twice • 5I does not receive torque There is a maintenance work order from October 25th that modified the Jake brake torque program due to high rejects for mislocations 5 5 S1 S2 S3 S4 S5 S6 S7 Step 4: Determine the assignable cause(s) There is no product verification after modifying the robot’s program Current Process Mapping 1. Quality reviews “critical torque equipment reject rates vs control limits” failures using “ToolsNet” • This analytical tool captures ESN, engine model, robot, time, bolt, torque values, reject/accept status and angle of fastener if subjected to angle requirements 2. Items out of the control limits are reviewed in the daily production meeting 3. Maintenance will review the data to understand possible correlation to product models, equipment, symptoms of failure and devise a course of action to address the failure The process failed to detect the issue Station 445 runs down the cap screws to 15Nm so #5I appeared tight and was able to pass hot test Toolsnet data for the engines all passed • The rocker pedestal cap screw program loosens the cap screw and performs a burnished step before applying the 65Nm torque 6 6 S1 S2 S3 S4 S5 S6 S7 Step 5: Select and verify an effective permanent solution The permanent solution will validate the product after robot program changes No. Description Target Date Status 1 Implement a quality alert regarding MCR requirement for reteaching torque related program changes 3/23 Complete 2 Establish quality verification process for any changes made #449 robot and torque programming (Standard QSI procedure, check list for product verification and notification/signoff(s)) 3/26 In process 3 Establish plan for periodic product verification for all robot cells 3/28 In process 4 Revisit FMEA and control plans for all robot cells 3/30 In process 5 Need to investigate to add break away torque monitoring condition or add forward cycle and monitor re-hit condition before rotating counter clockwise for burnishing cycle 4/5 In process 7 7 S1 S2 S3 S4 S5 S6 S7 Step 6: Plan and Implement Permanent Solution The permanent actions are in the process of being implemented More information to be provided after implementation 2018/3/26 8 8 S1 S2 S3 S4 S5 S6 S7 Step 7: Quantify the long term effectiveness Monitor effectiveness More information to be provided after Step 6 implementation 2018/3/26 9 9 11 11