Service Bulletin – Product

Subject: Clutch Release System Wear/Damage – Endurant and PACCAR
Transmissions
Document Number: TAIB-0889
Updated: July 12, 2021

Date: February 1, 2021

Issue Description:
Over repair/under repair of the Clutch Release System (and/or clutch) due to a lack of
troubleshooting wear measurement criteria. For scenarios other than customers
experiencing an illuminated transmission service lamp and Fault Code 511 (SPN
5614) or Fault Code 512 (SPN 5615) with FMI 16 which is covered in TAIB0885.
Containment/Corrective Action:
Document Clutch Release System and/or Clutch Diaphragm Spring wear
troubleshooting measurement criteria and Clutch Release System damage to look for
per this TAIB.
Affected Models/Population:
• Endurant Transmissions
• PACCAR Transmissions
Field Strategy:
If the transmission is removed from the vehicle and the technician notices wear to the
clutch diaphragm spring fingers and/or clutch release bearing, perform the clutch
system inspection detailed in the Service Strategy section.
Service Strategy:
Reference Endurant HD Automated Transmission Service Manual TRSM0950 for all
service procedures.
1. Inspect Input Shaft Pilot Bearing Wear Sleeve for excessive wear.
•

If excessive wear is found, inspect the pilot bearing for wear and/or
failure.
 If pilot bearing wear and/or failure is found, replace pilot bearing
per OEM guidelines
Note: Pilot bearing replacement is non-warrantable.
 If Input Shaft Pilot Bearing Wear Sleeve wear and/or damage is
found, replace Input Shaft Pilot Bearing Wear Sleeve.
Note: Input Shaft Pilot Bearing Wear Sleeve wear and/or damage
is non-warrantable
 Go to Step 2.
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Service Bulletin – Product

•

If no excessive wear is found, go to Step 2.

2. Inspect Release Bearing for wear and/or “divots” on wear pads from rollers.
Document the wear measurements in the warranty claim notes. (Reference
Image A.)
•

If wear is found, measure wear with a caliper.
 If wear and/or “divot” measurement exceeds 0.5 mm in depth,
replace the Release Bearing assembly and the Release Yoke. Go
to Step 5.
 If wear and/or “divot” measurement is less than 0.5 mm, go to
Step 3.

•

If no wear is found, go to Step 3.

Image A:
Release Bearing “Divot” Example:

“Divot” Measurement with caliper.

3. Inspect Release Bearing assembly face for wear. (Reference Image B.)
•

If wear is found, measure wear with a caliper (Reference Image C).
Document the wear measurements in the warranty claim notes. If the
outside chamfered edge is worn off (reference Image B), then no need to
measure the wear, but document “outside chamfered edge is worn off” in
the warranty claim notes.
 If wear measurement exceeds 0.75 mm or if the outside
chamfered edge is worn off (reference Image B), replace the
Release Bearing Assembly. Go to Step 5.
 If wear measurement is less than 0.75 mm, go to Step 4.
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Service Bulletin – Product
•

If no wear is found, go to Step 4.

Image B: Release Bearing Assembly Face Inspection
Wear present
Chamfered edge is worn
off (“circumferential” wear)

“Trapezoidal” wear

No wear present
New

Image C: Release Bearing Face Wear Measurement:
“Circumferential” wear

4. Rotate the Release Bearing by hand.
•

If the Release Bearing is hard to turn (seized or partially seized), or has
evidence of lack of lubrication, replace the Release Bearing Assembly.
Go to Step 5.

•

If the Release Bear rotates freely, go to Step 5.

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Service Bulletin – Product
5. Inspect the Clutch Diaphragm Spring for wear. Document the finger thickness
measurements in the warranty claim notes. (Reference Image D.)
•

If wear is found, measure wear with a micrometer.
 If the thinnest finger thickness measurement is less than 4.0 mm,
replace the clutch assembly, release bearing and pilot bearing
wear sleeve (clutch kit).
 If the thinnest finger thickness measurement is greater than 4.0
mm, go to Step 6.

•

If no wear is found, go to Step 6.

Image D: Diaphragm Spring Wear
Worn (Less than 4.0mm)

No wear (New)

6. Inspect the Release Yoke Pivot Pin, Release Yoke assembly and the plastic
sockets for damage. (Reference Image E.)
•

If Release Yoke Pivot Pin and/or Release Yoke and/or plastic sockets
are damaged, replace Release Yoke Assembly and Release Yoke Pivot
Pin.

•

If no wear is observed, reuse Release Yoke Pivot Pin.

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Service Bulletin – Product
IMAGE E: Release Yoke and Plastic Sockets Inspection

7. If no observed Clutch Release System and/or Clutch Diaphragm Spring
damage or wear is within the acceptable limits in this TAIB-0889, continue with
troubleshooting as appropriate.
Warranty Information:
Warranty Parts (if warrantable):
• K-4379 / K-4379-PAC / K-4488CL Clutch Service Kit (PACCAR X15 / Paccar
MX / Navistar X15 / Navistar A26)
• K-4437 / K-4494CL (Volvo X15)
• K-4496CL (DTNA)
• K-4489CL (DT 12 Aftermarket)
• K-4380 Release Yoke Assembly Kit
• 10001949 Release Yoke Pivot Pin
• 125968 Release Bearing (Volvo X15, DTNA)
• 125969 Release Bearing (PACCAR X15 / PACCAR MX / Navistar X15 /
Navistar A26)
Warranty Labor (if warrantable):
• Diagnostics (1.0 hour)
• Software Update (0.5 hour)
• Clutch R&R – Includes transmission R&R (OEM SRTs)
• Release Yoke R&R (0.1 hour)
• Release Yoke Pivot Pin R&R (0.1 hour)
• Clutch Calibration (0.5 hour)
• Test Drive (0.5 hour)

The material contained in this bulletin is product improvement information. Eaton Corporation is not committed to,
FSUD: 2020-FSUD-4226
or liable for, canvassing existing products.

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