TIB 26-022; Mismatch of Allison Hardware and Engine Calibration Software

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SB-10046161-2091

Technical Information Bulletin
26-022

Section
Transmission - 26

Subject
Campaign to Correct Mismatch of Allison Hardware and Kenworth Software

Release Date
8/24/2012

Condition
Listed chassis were built with a mismatch of Allison hardware and engine calibration software.

Chassis Affected
74 T270s and T370s built between 01/04/10 – 04/01/10 and equipped with Allison 2000 series transmissions
and PACCAR PX-6 engines.

Action
Review DWC or SIR online systems to verify that campaign “26-22” is still open or already completed prior to
performing this repair.
This is a repair that must be undertaken at an Allison authorized repair shop. If your dealership is Allison
certified, obtain Allison authorization and complete repairs per TAC Tip TT7252EN, then file for warranty with
Kenworth. If your dealership is not Allison certified, coordinate with your local Allison repair shop, schedule
with the customer, and file warranty as a sublet repair with Kenworth.

TIB 26-022; Mismatch of Allison Hardware and Engine Calibration Software

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Warranty
Kenworth will pay for repairs completed within Basic Vehicle Warranty or by 12/31/12, whichever is greater.
For Allison authorized dealerships, repairs must be authorized by Allison (ref TAC Tip TT7252EN) with
warranty claims filed through Kenworth for dealer cost of parts plus 30% and labor. For non-Allison dealers,
repairs must be completed by the local Allison repair facility and the repair expense filed as a sublet through
Kenworth warranty for sublet cost plus 15% markup.
CODING:

Failure Location: 027-038-001
Failure Type: 363
SRT Code: 026-XXX
Campaign code: 26-22

Work Accomplished: 58
Responsibility Code: 01
Claim Type: N
Refer to TIB 26-022 in the Complaint/Cause/Correction field

Parts
Parts, if required, are available through the Allison distribution system.

Background
Listed chassis were built with model year 2009 software for the Transmission Control Module (TCM)
calibration, but model year 2010 hardware. The result is improper hydraulic pressure for shift control.
Customers may experience poor shift quality, and there may be overheating and premature wear on the
torque converter. The repair includes calibration correction, inspection of the torque converter and, if
necessary, replacing any excessively worn components.

Procedure
Repair instructions are included in Allison TAC Tip TT7252EN. Most repairs (estimated 95%) will require
transmission control module (TCM) calibration and torque converter inspection only; approximately 2 hours at
the Allison repair shop. If transmission damage is identified, repairs will take longer, possibly including an
additional 24-28 hours to obtain replacement parts.
For Kenworth dealers who are Allison certified, obtain authorization and complete repairs per Allison TAC Tip
TT7252EN. File for warranty with Kenworth.
For Kenworth dealers who are not Allison certified, coordinate with your local Allison repair shop, then
schedule with the customer. and file warranty as a sublet repair with Kenworth.

Attachments
TIB 26-022, Allison TT7252EN.pdf
TIB 26-022 Chassis List.xls
TIB 26-022 Customer Letter.pdf

TIB 26-022; Mismatch of Allison Hardware and Engine Calibration Software

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