L9 – Jake Brake
#5 Intake rocker pedestal
cap screw not fully torqued

March 26, 2018
Confidential

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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
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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

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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

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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

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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”
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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

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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

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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

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Step 7: Quantify the long term effectiveness

Monitor effectiveness
 More information to be provided after Step 6 implementation

2018/3/26

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