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ISX15/X15 Cam Idler Shaft Miss-assembly
Thursday, May 27, 2021 12:53:34 PM
Screening-repair proc thru cyl head w valve cover rmvd.ppt.pptx

,
Hope things are well.
I am reaching out to request permission to have our Cummins Technicians screen
JEP engines for a suspect idler shaft miss-assembly on the engine.
Please refer to the attached 1-page summary for details on the issue.
Also included is the OEM inspection process for Cummins techs.
Cummins JEP has already began containment for this issue.
We have started screening engines in-house for miss-assembled cam idler shaft.
The Screening process will involve checking cam idler assembly for conformance.
Suspect miss-assembled cam idler shafts can be repaired by the Cummins tech.
Please advise and with your permission we can let the Cummins tech know and begin
screening immediately.
We will be sending the list of suspect Engines and Chassis numbers to our On-site
mechanics and work with them on getting Engines screened.
Here’s a breakdown on suspect ESN shipped by Navistar Escobedo facilities
80340081
80340518
80340519
80340520
80341327
80341328
80341329
80341330
80341331
80341332
80341333
80341334
80341336
80341337
80341338
80341339
80341320

JEP Customer Quality Manager

Cummins
Jamestown Engine Plant
4720 Baker St. Ext, Lakewood, NY 14750

ISX15/X15
Cam Idler
Shaft Missassembly
May 27, 2021

ISX15/X15 Cam Idler Shaft Miss-assembly

Update Date: 4/13/21

Issue: JEP has found ISX15/X15 Cam Idler Shaft Miss-assembled.
JEP Build Range Focus: May 21, 2021 – May 24, 2021
Suspected ESN Count: – 34 Engines. Impacts ISX15/X15 engine families.
Assignable Cause: Operator error.
Customer Experience: Potential for premature failure of cam idler bushing and/or gear train failure.
Short Term Actions Complete:
 JEP containment – 100% screening and repair on in house engines.
 Clean Point Date: May 25, 2021 ; ESN 1st ISX/X15 80340856
Next Steps:
 Initiate screening and repair activity at OEMs – May 27, 2021
 Recommend OEM to hold suspect ESN list until screening is completed.
1. Suspect engines to be repaired by onsite techs.
2. ESNs without suspect miss-assembled cam idler shaft are good to ship.
 OEM to communicate number of units that have shipped.
 CMI to evaluate next steps on any potential field action.

Cummins Confidential

2

ISX15/X15 Cam
Idler Shaft Missassembly
screening
(through cylinder head)
(CAD photos provided by
Ref. EQR JEP-PIC-2021-00522
5/26/2021
Cummins Confidential

)

Background on Issue
 Suspect engines with cam idler gear potentially
miss-assembled.
 There were two potential types of missassembly:
• Idler shaft installed upside down
• Idler shaft clocked in the wrong direction
 These miss-assembly scenarios affect the oil
feed to the bushing and/or gear mesh and can
result in premature gear bushing and/or
geartrain failure.

4

Original Screening Process
 Gear cover was removed, and hole was checked to make sure it lines up thru the retainer plate, idler shaft, all the way
to the cylinder head oil feed hole

Examples of properly assembled

Examples of mis-assembled

5

Less intrusive screening Process Background
 It was discovered that, rather than having to remove
the gear cover and other options installed on or near
the gear cover, this defect can be screened by simply
removing the valve cover instead.
 See CAD section view of the cam idler gear subassembly shown to the right:

Cam Idler plate

Retainer
plate

 In a properly assembled sub-assembly, a hole should
line up from the cylinder head oil feed hole thru to
the inside of the gear cover (shown by the red arrow).
Cylinder head
Cam Idler
Shaft

6

Less intrusive screening Process Background

Hole will only go to
this point if missassembled

 In a miss-assembled cam idler gear subassembly, the hole will be blocked off at
the cam idler plate that goes between
the cylinder head and the gear housing.
 It was found that a rod could be inserted
through the cylinder head feedhole to
confirm if the exit of the oil feed hole was
blocked off by the miss-assembled idler
shaft.

7

Screening process through cylinder head:
 Step 1: Remove valve cover following normal QSOL procedures.
 Step 2: Obtain a small diameter, semi flexible rod or similar that is at least 200 mm long.
 Step 3: Make a mark on the rod where the edge of the mark ends at 80mm.
Make edge of mark 80 mm from end of rod

8

Screening process through cylinder head:
 Step 4: Insert rod as far as possible through the
cam idler oil feed thru hole in the cylinder head
(near the front, left corner of the cylinder head in
front of the #1 HPC casting feature).
 Step 5:

Use Cylinder head
inside casting surface
as a rough datum to
check whether mark on
rod is visible.

• Pass: If mark on rod cannot be seen
(meaning that rod was able to be inserted
at least 80 mm past the cylinder head cast
surface before it stops).
• Fail: If mark on rod can seen (meaning
rod cannot be inserted more than 80 mm
past the cylinder head cast surface).
 See Appendix for more section photos
illustrating how this screening process can
detect miss-assembled idler shafts.
9

Repair of Misassembled Cam Idler gear
 Remove gear cover and options per Quick Serve procedure 175-001-003-tr
 Remove cam idler gear retainer, cam idler gear and cam idler plate.
 Reorientate the cam idler plate and gear so that oil hole is visible, reinstall and secure
with cap screws per Quick Serve procedure 175-001-003-tr

10

11
11

Rod should only insert ~31.5
mm from the inside cyl. Head
cast surface if cam idler gear
shaft is miss-assembled.

12

It takes ~77.6 mm to get from
the inside cast surface to the
outside face of the gear
retainer.

13

The rod should insert ~110mm
on a properly assembled cam
idler shaft because the rod will
be able to go all the way to the
inside of the gear cover.

14